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  • 1.
    Zhao, Mingduo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Fridberger, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Bone conduction hearing in the Guinea pig and the effect of artificially induced middle ear lesions2019In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 379, p. 21-30Article in journal (Refereed)
    Abstract [en]

    Although human bone conduction (BC) hearing is well investigated, there is a lack of information about BC hearing in most other species. In humans, the amount of conductive loss is estimated as the difference between the air conduction (AC) and BC thresholds. Similar estimations for animals are difficult since in most species, the normal BC hearing thresholds have not been established. In the current study, the normal BC thresholds in the frequency range between 2 kHz and 20 kHz are investigated for the Guinea pig. Also, the effect of a middle ear lesion, here modelled by severing the ossicles (ossicular discontinuity) and gluing the ossicles to the bone (otosclerosis), is investigated for both AC and BC. The hearing thresholds in the Guinea pigs were estimated by a regression of the amplitude of the compound action potential (CAP) with stimulation level and was found robust and gave a high resolution of the threshold level. The reference for the BC thresholds was the cochlear promontory bone velocity. This reference enables comparison of BC hearing in animals, both intra and inter species, which is independent on the vibrator and stimulation position. The vibration was measured in three orthogonal directions where the dominating vibration directions was in line with the stimulation direction, here the ventral direction. The BC thresholds lay between -10 and 3 dB re 1 mu m/s. The slopes of CAP growth function were similar for AC and BC at low and high frequencies, but slightly lower for BC than AC at frequencies between 8 and 16 kHz. This was attributed to differences in the stimulus levels used for the slope estimation and not a real difference in CAP slopes between the stimulation modalities. Two kinds of middle ear lesions, ossicular discontinuity and stapes glued to the surrounding bone, gave threshold shifts of between 23 and 53 dB for AC while it was below 16 dB when the stimulation was by BC. Statistically different threshold shifts between the two types of lesions were found where the AC threshold shifts for a glued stapes at 2 and 4 kHz were 9-18 dB greater than for a severed ossicular chain, and the BC threshold shifts for a glued stapes at 4 and 12 kHz were 8-9 dB greater than fora severed ossicular chain. (C) 2019 Elsevier B.V. All rights reserved.

  • 2.
    Chang, You
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Characteristics of Bone-Conduction Devices Simulated in a Finite-Element Model of a Whole Human Head2019In: TRENDS IN HEARING, ISSN 2331-2165, Vol. 23, article id 2331216519836053Article in journal (Refereed)
    Abstract [en]

    Nowadays, many different kinds of bone-conduction devices (BCDs) are available for hearing rehabilitation. Most studies of these devices fail to compare the different types of BCDs under the same conditions. Moreover, most results are between two BCDs in the same subject, or two BCDs in different subjects failing to provide an overview of the results between several of the BCDs. Another issue is that some BCDs require surgical procedures that prevent comparison of the BCDs in the same persons. In this study, four types of skin-drive BCDs, three direct-drive BCDs, and one oral device were evaluated in a finite-element model of the human head that was able to simulate all BCDs under the same conditions. The evaluation was conducted using both a dynamic force as input and an electric voltage to a model of a BCD vibrator unit. The results showed that the direct-drive BCDs and the oral device gave vibration responses within 10 dB at the cochlea. The skin-drive BCDs had similar or even better cochlear vibration responses than the direct-drive BCDs at low frequencies, but the direct-drive BCDs gave up to 30 dB higher cochlear vibration responses at high frequencies. The study also investigated the mechanical point impedance at the interface between the BCD and the head, providing information that explains some of the differences seen in the results. For example, when the skin-drive BCD attachment area becomes too small, the transducer cannot provide an output force similar to the devices with larger attachment surfaces.

  • 3.
    Nuttall, Alfred L.
    et al.
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Ricci, Anthony J.
    Stanford Univ, CA 94025 USA; Stanford Univ, CA 94025 USA.
    Burwood, George
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Harte, James M.
    Tech Univ Denmark, Denmark.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Caye-Thomasen, Per
    Copenhagen Univ Hosp, Denmark.
    Ren, Tianying
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Ramamoorthy, Sripriya
    Indian Inst Technol, India.
    Zhang, Yuan
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Wilson, Teresa
    Oregon Hlth and Sci Univ, OR 97239 USA.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Oticon AS, Denmark.
    Moore, Brian C. J.
    Univ Cambridge, England.
    Fridberger, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Oregon Hlth and Sci Univ, OR 97239 USA.
    A mechanoelectrical mechanism for detection of sound envelopes in the hearing organ2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, article id 4175Article in journal (Refereed)
    Abstract [en]

    To understand speech, the slowly varying outline, or envelope, of the acoustic stimulus is used to distinguish words. A small amount of information about the envelope is sufficient for speech recognition, but the mechanism used by the auditory system to extract the envelope is not known. Several different theories have been proposed, including envelope detection by auditory nerve dendrites as well as various mechanisms involving the sensory hair cells. We used recordings from human and animal inner ears to show that the dominant mechanism for envelope detection is distortion introduced by mechanoelectrical transduction channels. This electrical distortion, which is not apparent in the sound-evoked vibrations of the basilar membrane, tracks the envelope, excites the auditory nerve, and transmits information about the shape of the envelope to the brain.

  • 4.
    Keceli, Sumru
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Measurements of bone conduction auditory brainstem response with the new audiometric bone conduction transducer Radioear B812018In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 57, no 8, p. 577-583Article in journal (Refereed)
    Abstract [en]

    Objective: To compare recordings of bone conduction (BC) stimulated auditory brainstem response (ABR) obtained using the newer BC transducer Radioear B81 and the conventional BC transducer Radioear B71. Balanced electromagnetic separation transducer (BEST) design found in the B81 may influence the ABR magnitudes and latencies, as well as electrical artefacts. Design: ABRs to tone burst stimuli of 500 Hz, 2000 Hz, 4000 Hz, click stimulation, and broad-band chirp stimulation at 20 and 50dB nHL were recorded. For each device, stimulus and intensity level, the ABR Jewett wave V amplitude and latency were obtained. The device-related electrical stimulus artefacts on the ABR recordings were also analysed by calculating the Hilbert envelope of the peri-stimulus recording segments. Study sample: Twenty-three healthy adults with normal hearing were included in the study. Results: The ABRs obtained by the B81 were similar to that of the B71 in terms of ABR wave V amplitude and latency. However, the B81 produced smaller electrical artefacts than B71 and this difference was statistically significant. Conclusions: The BC transducer Radioear B81 provides ABRs comparable to Radioear B71 while causing smaller artefacts.

  • 5.
    Hengen, Johanna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lundeborg Hammarström, Inger
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Perceived Voice Quality and Voice-Related Problems Among Older Adults With Hearing Impairments2018In: Journal of Speech, Language and Hearing Research, ISSN 1092-4388, E-ISSN 1558-9102, Vol. 61, no 9, p. 2168-2178Article in journal (Refereed)
    Abstract [en]

    The auditory system helps regulate phonation. A speakers perception of their own voice is likely to be of both emotional and functional significance. Although many investigations have observed deviating voice qualities in individuals who are prelingually deaf or profoundly hearing impaired, less is known regarding how older adults with acquired hearing impairments perceive their own voice and potential voice problems. Purpose: The purpose of this study was to investigate problems relating to phonation and self-perceived voice sound quality in older adults based on hearing ability and the use of hearing aids. Method: This was a cross-sectional study, with 290 participants divided into 3 groups (matched by age and gender): (a) individuals with hearing impairments who did not use hearing aids (n = 110), (b) individuals with hearing impairments who did use hearing aids (n = 110), and (c) individuals with no hearing impairments (n = 70). All participants underwent a pure-tone audiometry exam; completed standardized questionnaires regarding their hearing, voice, and general health; and were recorded speaking in a soundproof room. Results: The hearing aid users surpassed the benchmarks for having a voice disorder on the Voice Handicap Index (VHI; Jacobson et al., 1997) at almost double the rate predicted by the Swedish normative values for their age range, although there was no significant difference in acoustical measures between any of the groups. Both groups with hearing impairments scored significantly higher on the VHI than the control group, indicating more impairment. It remains inconclusive how much hearing loss versus hearing aids separately contribute to the difference in voice problems. The total scores on the Hearing Handicap Inventory for the Elderly (Ventry amp; Weinstein, 1982), in combination with the variables gender and age, explained 21.9% of the variance on the VHI. Perceiving ones own voice as being distorted, dull, or hollow had a strong negative association with a general satisfaction about the sound quality of ones own voice. In addition, groupwise differences in own-voice descriptions suggest that a negative perception of ones voice could be influenced by alterations caused by hearing aid processing. Conclusions: The results indicate that hearing impairments and hearing aids affect several aspects of vocal satisfaction in older adults. A greater understanding of how hearing impairments and hearing aids relate to voice problems may contribute to better voice and hearing care.

  • 6.
    Chang, You
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Kim, Namkeun
    Incheon Natl Univ, South Korea.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Simulation of the power transmission of bone-conducted sound in a finite-element model of the human head2018In: Biomechanics and Modeling in Mechanobiology, ISSN 1617-7959, E-ISSN 1617-7940, Vol. 17, no 6, p. 1741-1755Article in journal (Refereed)
    Abstract [en]

    Bone conduction (BC) sound is the perception of sound transmitted in the skull bones and surrounding tissues. To better understand BC sound perception and the interaction with surrounding tissues, the power transmission of BC sound is investigated in a three-dimensional finite-element model of a whole human head. BC sound transmission was simulated in the FE model and the power dissipation as well as the power flow following a mechanical vibration at the mastoid process behind the ear was analyzed. The results of the simulations show that the skull bone (comprises the cortical bone and diploe) has the highest BC power flow and thereby provide most power transmission for BC sound. The soft tissues was the second most important media for BC sound power transmission, while the least BC power transmission is through the brain and the surrounding cerebrospinal fluid (CSF) inside the cranial vault. The vibrations transmitted in the skull are mainly concentrated at the skull base when the stimulation is at the mastoid. Other vibration transmission pathways of importance are located at the occipital bone at the posterior side of the head while the transmission of sound power through the face, forehead and vertex is minor. The power flow between the skull bone and skull interior indicate that some BC power is transmitted to and from the skull interior but the transmission of sound power through the brain seem to be minimal and only local to the brain-bone interface.

  • 7.
    Kim, Jun Woo
    et al.
    Korea Univ, South Korea.
    Bae, Kiho
    Korea Univ, South Korea; KIST, South Korea.
    Kim, Hyun Joong
    Korea Univ, South Korea.
    Son, Ji-won
    KIST, South Korea; Korea Univ Sci and Technol UST, South Korea.
    Kim, Nam Keun
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Incheon Natl Univ, South Korea.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Prinz, Fritz B.
    Stanford Univ, CA 94305 USA; Stanford Univ, CA 94305 USA.
    Shim, Joon Hyung
    Korea Univ, South Korea; Stanford Univ, CA 94305 USA.
    Three-dimensional thermal stress analysis of the re-oxidized Ni-YSZ anode functional layer in solid oxide fuel cells2018In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 752, p. 148-154Article in journal (Refereed)
    Abstract [en]

    Nickel-yttria-stabilized zirconia (Ni-YSZ) cermet is widely used as an anode material in solid oxide fuel cells (SOFCs); however, Ni re-oxidation causes critical problems due to volume expansion, which causes high thermal stress. We fabricated a Ni-YSZ anode functional layer (AFL), which is an essential component in high-performance SOFCs, and re-oxidized it to investigate the related three-dimensional (3D) microstructural and thermo-mechanical effects. A 3D model of the re-oxidized AFL was generated using focused ion beam-scanning electron microscope (FIB-SEM) tomography. Re-oxidation of the Ni phase caused significant volumetric expansion, which was confirmed via image analysis and calculation of the volume fraction, connectivity, and two-phase boundary density. Finite element analysis (FEA) with simulated heating to 500-900 degrees C confirmed that the thermal stress in re-oxidized Ni-YSZ is concentrated at the boundaries between YSZ and re-oxidized NiO (nickel oxide). NiO is subjected to more stress than YSZ. Stress exceeding the fracture stress of 8 mol% YSZ appears primarily at 800 degrees C or higher. The stress is also more severe near the electrolyte-anode boundary than in the Ni-YSZ cermet and the YSZ regions. This may be responsible for the electrolyte membrane delamination and fracture that are observed during high-temperature operation. (C) 2018 Elsevier B.V. All rights reserved.

  • 8.
    Skagerstrand, Åsa
    et al.
    Örebro University Hospital, Sweden; Örebro University, Sweden; Swedish Institute Disabil Research, Sweden.
    Kobler, Susanne
    Örebro University Hospital, Sweden; Örebro University, Sweden; Swedish Institute Disabil Research, Sweden.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences. Swedish Institute Disabil Research, Sweden.
    Loudness and annoyance of disturbing sounds - perception by normal hearing subjects2017In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 56, no 10, p. 775-783Article in journal (Refereed)
    Abstract [en]

    Objective: Sounds in the daily environment may cause loudness and annoyance. The present study investigated the perception of loudness and annoyance for eight different sounds present in a daily sound environment and at nine different levels varying by +/- 20 dB around the recorded level. The outcomes were related to tests of participants auditory and cognitive abilities. Design: The participants undertook auditory and working memory (WM) tests prior to ratings of everyday sounds previously shown to be disturbing for persons with hearing impairment (hearing aid users). Study sample: Twenty-one participants aged between 24 and 71 years, with normal hearing threshold levels. Results: Both perceived loudness and annoyance were primarily driven by the sound level. Sounds emitted from paper were rated as having greater loudness and being more annoying than the other sound sources at the same sound level. Auditory and cognitive abilities did not influence the perception of loudness and annoyance. Conclusions: Loudness and annoyance ratings were mainly driven by sound level. Expectations of a sound seemed to influence the assessment of loudness and annoyance while auditory performance and WM capacity showed no influence on the ratings.

  • 9.
    Dobrev, Ivo
    et al.
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Hoon Sim, Jae
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Speech language pathology, Audiology and Otorhinolaryngology. Linköping University, Faculty of Medicine and Health Sciences.
    Ihrle, Sebastian
    University of Stuttgart, Germany.
    Gerig, Rahel
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Pfiffner, Flurin
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Eiber, Albrecht
    University of Stuttgart, Germany.
    Huber, Alexander M.
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Roosli, Christof
    University Hospital Zurich, Switzerland; University of Zurich, Switzerland.
    Sound wave propagation on the human skull surface with bone conduction stimulation2017In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 355Article in journal (Refereed)
    Abstract [en]

    Background: Bone conduction (BC) is an alternative to air conduction to stimulate the inner ear. In general, the stimulation for BC occurs on a specific location directly on the skull bone or through the skin covering the skull bone. The stimulation propagates to the ipsilateral and contralateral cochlea, mainly via the skull bone and possibly via other skull contents. This study aims to investigate the wave propagation on the surface of the skull bone during BC stimulation at the forehead and at ipsilateral mastoid. Methods: Measurements were performed in five human cadaveric whole heads. The electro-magnetic transducer from a BCHA (bone conducting hearing aid), a Baha (R) Cordelle II transducer in particular, was attached to a percutaneously implanted screw or positioned with a 5-Newton steel headband at the mastoid and forehead. The Baha transducer was driven directly with single tone signals in the frequency range of 0.25-8 kHz, while skull bone vibrations were measured at multiple points on the skull using a scanning laser Doppler vibrometer (SLDV) system and a 3D LDV system. The 3D velocity components, defined by the 3D LDV measurement coordinate system, have been transformed into tangent (in-plane) and normal (out-of-plane) components in a local intrinsic coordinate system at each measurement point, which is based on the cadaver heads shape, estimated by the spatial locations of all measurement points. Results: Rigid-body-like motion was dominant at low frequencies below 1 kHz, and clear transverse traveling waves were observed at high frequencies above 2 kHz for both measurement systems. The surface waves propagation speeds were approximately 450 m/s at 8 kHz, corresponding trans-cranial time interval of 0.4 ms. The 3D velocity measurements confirmed the complex space and frequency dependent response of the cadaver heads indicated by the ID data from the SLDV system. Comparison between the tangent and normal motion components, extracted by transforming the 3D velocity components into a local coordinate system, indicates that the normal component, with spatially varying phase, is dominant above 2 kHz, consistent with local bending vibration modes and traveling surface waves. Conclusion: Both SLDV and 3D LDV data indicate that sound transmission in the skull bone causes rigid body-like motion at low frequencies whereas transverse deformations and travelling waves were observed above 2 kHz, with propagation speeds of approximately of 450 m/s at 8 kHz. (C) 2017 Elsevier B.V. All rights reserved.

  • 10.
    Stenfelt, Stefan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Eriksholm Research Centre, Oticon A/S, Helsingor, Denmark.
    Ng, Elaine
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Lidestam, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Zekveld, Adriana
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. VU University Medical Center, Amsterdam, Netherlands.
    Sörqvist, Patrik
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. University of Gävle, Gävle, Sweden.
    Lyxell, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Träff, Ulf
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Yumba, Wycliffe
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Classon, Elisabet
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Hällgren, Mathias
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Larsby, Birgitta
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Signoret, Carine
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Pichora-Fuller, Kathleen
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. University of Toronto, Toronto, Canada.
    Rudner, Mary
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Danielsson, Henrik
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Rönnberg, Jerker
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Auditory, signal processing, and cognitive factors  influencing  speech  perception  in  persons with hearing loss fitted with hearing aids – the N200 study2016Conference paper (Other academic)
    Abstract [en]

    Objective: The aim of the current study was to assess aided speech-in-noise outcomes and relate those measures to auditory sensitivity and processing, different types of cognitive processing abilities, and signal processing in hearing aids.

    Material and method: Participants were 200 hearing-aid wearers, with a mean age of 60.8 years, 43% females, with average hearing thresholds in the better ear of 37.4 dB HL. Tests of auditory functions were hearing thresholds, DPOAEs, tests of fine structure processing, IHC dead regions, spectro-temporal modulation, and speech recognition in quiet (PB words). Tests of cognitive processing function were tests of phonological skills, working memory, executive functions and inference making abilities, and general cognitive tests (e.g., tests of cognitive decline and IQ). The outcome test variables were the Hagerman sentences with 50 and 80% speech recognition levels, using two different noises (stationary speech weighted noise and 4-talker babble), and three types of signal processing (linear gain, fast acting compression, and linear gain plus a non-ideal binary mask). Another sentence test included typical and atypical sentences with contextual cues that were tested both audio-visually and in an auditory mode only. Moreover, HINT and SSQ were administrated.

    Analysis: Factor analyses were performed separate for the auditory, cognitive, and outcome tests.

    Results: The auditory tests resulted in two factors labeled SENSITIVITY and TEMPORAL FINE STRUCTURE, the cognitive tests in one factor (COGNITION), and the outcome tests in the two factors termed NO CONTEXT and CONTEXT that relates to the level of context in the different outcome tests. When age was partialled out, COGNITION was moderately correlated with the TEMPORAL FINE STRUCTURE and NO CONTEXT factors but only weakly correlated with the CONTEXT factor. SENSITIVITY correlated weakly with TEMPORAL FINE STRUCTURE and CONTEXT, and moderately with NO CONTEXT, while TEMPORAL FINE STRUCTURE showed weak correlation with CONTEXT and moderate correlation with NO CONTEXT. CONTEXT and NO CONTEXT had a  moderate correlation. Moreover, the overall results of the Hagerman sentences showed 0.9 dB worse SNR with fast acting compression compared with linear gain and 5.5 dB better SNR with linear  gain and noise reduction compared with only linear gain.

    Conclusions: For hearing aid wearers, the ability to recognize speech in noise is associated with both sensory and cognitive processing abilities when the speech materials have low internal context. These associations are less prominent when the speech material has contextual cues.

  • 11.
    Zeitooni, Mehrnaz
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Mäki-Torkko, Elina
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Binaural Hearing Ability With Bilateral Bone Conduction Stimulation in Subjects With Normal Hearing: Implications for Bone Conduction Hearing Aids.2016In: Ear and Hearing, ISSN 0196-0202, E-ISSN 1538-4667, Vol. 37, no 6, p. 690-702Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: The purpose of this study is to evaluate binaural hearing ability in adults with normal hearing when bone conduction (BC) stimulation is bilaterally applied at the bone conduction hearing aid (BCHA) implant position as well as at the audiometric position on the mastoid. The results with BC stimulation are compared with bilateral air conduction (AC) stimulation through earphones.

    DESIGN: Binaural hearing ability is investigated with tests of spatial release from masking and binaural intelligibility level difference using sentence material, binaural masking level difference with tonal chirp stimulation, and precedence effect using noise stimulus.

    RESULTS: In all tests, results with bilateral BC stimulation at the BCHA position illustrate an ability to extract binaural cues similar to BC stimulation at the mastoid position. The binaural benefit is overall greater with AC stimulation than BC stimulation at both positions. The binaural benefit for BC stimulation at the mastoid and BCHA position is approximately half in terms of decibels compared with AC stimulation in the speech based tests (spatial release from masking and binaural intelligibility level difference). For binaural masking level difference, the binaural benefit for the two BC positions with chirp signal phase inversion is approximately twice the benefit with inverted phase of the noise. The precedence effect results with BC stimulation at the mastoid and BCHA position are similar for low frequency noise stimulation but differ with high-frequency noise stimulation.

    CONCLUSIONS: The results confirm that binaural hearing processing with bilateral BC stimulation at the mastoid position is also present at the BCHA implant position. This indicates the ability for binaural hearing in patients with good cochlear function when using bilateral BCHAs.

  • 12.
    Strömberg, Anna-Karin
    et al.
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping. Karolinska Hospital, Sweden.
    Olofsson, Åke
    Karolinska Institute, Sweden.
    Westin, Magnus
    Karolinska Hospital, Sweden.
    Duan, Maoli
    Karolinska Hospital, Sweden; Karolinska Institute Stockholm, Sweden.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Changes in cochlear function related to acoustic stimulation of cervical vestibular evoked myogenic potential stimulation2016In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 340, p. 43-49Article in journal (Refereed)
    Abstract [en]

    Evaluation of cervical evoked myogenic potentials (c-VEMP) is commonly applied in clinical investigations of patients with suspected neurotological symptoms. Short intense acoustic stimulation of peak levels close to 130 dB SPL is required to elicit the responses. A recent publication on bilateral significant sensorineural hearing loss related to extensive VEMP stimulation motivates evaluations of immediate effects on hearing acuity related to the intense acoustic stimulation required to elicit c-VEMP responses. The aim of the current study was to investigate changes in DPOAE-levels and hearing thresholds in relation to c-VEMP testing in humans. More specifically, the current focus is on immediate changes in hearing thresholds and changes in DPOAE-levels at frequencies 0.5 octaves above the acoustic stimulation when applying shorter tone bursts than previously used. Hearing acuity before and immediately after exposure to c-VEMP stimulation was examined in 24 patients with normal hearing referred for neurotologic testing. The stimulation consisted of 192 tonebursts of 6 ms and was presented at 500 Hz and 130 dB peSPL. Bekesy thresholds at 0.125-8 kHz and DPOAE I/O growth functions with stimulation at 0.75 and 3 kHz were used to assess c-VEMP related changes in hearing status. No significant deterioration in Bekesy thresholds was detected. Significant reduction in DPOAE levels at 0.75 (0.5-1.35 dB) and 3 kHz (1.6-2.1 dB) was observed after c-VEMP stimulation without concomitant changes in cochlear compression. The results indicated that there was no immediate audiometric loss related to c-VEMP stimulation in the current group of patients. The significant reduction of DPOAE levels at a wider frequency range than previously described after the c-VEMP test could be related to the stimulation with shorter tone bursts. The results show that c-VEMP stimulation causes reduction in DPOAE-levels at several frequencies that corresponds to half the reductions in DPOAE levels reported after exposure to the maximally allowed occupational noise for an 8 h working day. Consequently, extended stimuli intensity or stimulation repetition with c-VEMP testing should be avoided to reduce the risk for noise-induced cochlear injury.

  • 13.
    Rönnberg, Jerker
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Oticon AS, Denmark.
    Ng, Elaine Hoi Ning
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lidestam, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Zekveld, Adriana
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, The Swedish Institute for Disability Research. Linköping University, Faculty of Arts and Sciences. Vrije University of Amsterdam, Netherlands; Vrije University of Amsterdam, Netherlands.
    Sörqvist, Patrik
    Linköping University, Department of Behavioural Sciences, Cognition, Development and Disability. Linköping University, Faculty of Arts and Sciences. University of Gavle, Sweden.
    Lyxell, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Träff, Ulf
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Yumba, Wycliffe
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Classon, Elisabet
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, The Swedish Institute for Disability Research. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Acute Internal Medicine and Geriatrics.
    Hällgren, Mathias
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Larsby, Birgitta
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Signoret, Carine
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Pichora-Fuller, Kathleen
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, The Swedish Institute for Disability Research. Linköping University, Faculty of Arts and Sciences. University of Toronto, Canada; University of Health Network, Canada; Baycrest Hospital, Canada.
    Rudner, Mary
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Danielsson, Henrik
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Hearing impairment, cognition and speech understanding: exploratory factor analyses of a comprehensive test battery for a group of hearing aid users, the n200 study2016In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 55, no 11, p. 623-642Article in journal (Refereed)
    Abstract [en]

    Objective: The aims of the current n200 study were to assess the structural relations between three classes of test variables (i.e. HEARING, COGNITION and aided speech-in-noise OUTCOMES) and to describe the theoretical implications of these relations for the Ease of Language Understanding (ELU) model. Study sample: Participants were 200 hard-of-hearing hearing-aid users, with a mean age of 60.8 years. Forty-three percent were females and the mean hearing threshold in the better ear was 37.4dB HL. Design: LEVEL1 factor analyses extracted one factor per test and/or cognitive function based on a priori conceptualizations. The more abstract LEVEL 2 factor analyses were performed separately for the three classes of test variables. Results: The HEARING test variables resulted in two LEVEL 2 factors, which we labelled SENSITIVITY and TEMPORAL FINE STRUCTURE; the COGNITIVE variables in one COGNITION factor only, and OUTCOMES in two factors, NO CONTEXT and CONTEXT. COGNITION predicted the NO CONTEXT factor to a stronger extent than the CONTEXT outcome factor. TEMPORAL FINE STRUCTURE and SENSITIVITY were associated with COGNITION and all three contributed significantly and independently to especially the NO CONTEXT outcome scores (R-2 = 0.40). Conclusions: All LEVEL 2 factors are important theoretically as well as for clinical assessment.

  • 14.
    Dobrev, Ivo
    et al.
    University of Zurich Hospital, Switzerland.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Roosli, Christof
    University of Zurich Hospital, Switzerland.
    Bolt, Lucy
    University of Zurich Hospital, Switzerland.
    Pfiffner, Flurin
    University of Zurich Hospital, Switzerland.
    Gerig, Rahel
    University of Zurich Hospital, Switzerland.
    Huber, Alexander
    University of Zurich Hospital, Switzerland.
    Hoon Sim, Jae
    University of Zurich Hospital, Switzerland.
    Influence of stimulation position on the sensitivity for bone conduction hearing aids without skin penetration2016In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 55, no 8, p. 439-446Article in journal (Refereed)
    Abstract [en]

    Objective: This study explores the influence of stimulation position on bone conduction (BC) hearing sensitivity with a BC transducer attached using a headband. Design:(1) The cochlear promontory motion was measured in cadaver heads using laser Doppler vibrometry while seven different positions around the pinna were stimulated using a bone anchored hearing aid transducer attached using a headband. (2) The BC hearing thresholds were measured in human subjects, with the bone vibrator Radioear B71 attached to the same seven stimulation positions. Study sample: Three cadaver heads and twenty participants. Results: Stimulation on a position superior-anterior to the pinna generated the largest promontory motion and the lowest BC thresholds. Stimulations on the positions superior to the pinna, the mastoid, and posterior-inferior to the pinna showed similar magnitudes of promontory motion and similar levels of BC thresholds. Conclusion: Stimulations on the regions superior to the pinna, the mastoid, and posterior-inferior to the pinna provide stable BC transmission, and are insensitive to small changes of the stimulation position. Therefore it is reliable to use the mastoid to determine BC thresholds in clinical audiometry. However, stimulation on a position superior-anterior to the pinna provides more efficient BC transmission than stimulation on the mastoid.

  • 15.
    Sim, J. H.
    et al.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Dobrev, I.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Gerig, R.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Pfiffner, F.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Huber, A. M.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Roosli, C.
    University of Zurich Hospital, Switzerland; University of Zurich, Switzerland.
    Interaction between osseous and non-osseous vibratory stimulation of the human cadaveric head2016In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 340, p. 153-160Article in journal (Refereed)
    Abstract [en]

    Bone conduction (BC) stimulation can be applied by vibration to the bony or skin covered skull (osseous BC), or on soft tissue such as the neck (non-osseous BC). The interaction between osseous and non osseous bone conduction pathways is assessed in this study. The relation between bone vibrations measured at the cochlear promontory and the intracranial sound pressure for stimulation directly on the dura and for stimulation at the mastoid between 0.2 and 10 kHz was compared. First, for stimulation on the dura, varying the static coupling force of the BC transducer on the dura had only a small effect on promontory vibration. Second, the presence or absence of intracranial fluid did not affect promontory vibration for stimulation on the dura. Third, stimulation on the mastoid elicited both promontory vibration and intracranial sound pressure. Stimulation on the dura caused intracranial sound pressure to a similar extent above 0.5 kHz compared to stimulation on the mastoid, while promontory vibration was less by 20-40 dB. From these findings, we conclude that intracranial sound pressure (non-osseous BC) only marginally affects bone vibrations measured on the promontory (osseous BC), whereas skull vibrations affect intracranial sound pressure. (C) 2016 Elsevier B.V. All rights reserved.

  • 16.
    Roosli, Christof
    et al.
    University of Zurich, Switzerland.
    Dobrev, Ivo
    University of Zurich, Switzerland.
    Hoon Sim, Jae
    University of Zurich, Switzerland.
    Gerig, Rahel
    University of Zurich, Switzerland.
    Pfiffner, Flurin
    University of Zurich, Switzerland.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Huber, Alexander M.
    University of Zurich, Switzerland.
    Intracranial Pressure and Promontory Vibration With Soft Tissue Stimulation in Cadaveric Human Whole Heads2016In: Otology and Neurotology, ISSN 1531-7129, E-ISSN 1537-4505, Vol. 37, no 9, p. E384-E390Article in journal (Refereed)
    Abstract [en]

    Hypothesis:Intracranial pressure and skull vibrations are correlated and depend on the stimulation position and frequency.Background:A hearing sensation can be elicited by vibratory stimulation on the skin covered skull, or by stimulation on soft tissue such as the neck. It is not fully understood whether different stimulation sites induce the skull vibrations responsible for the perception or whether other transmission pathways are dominant. The aim of this study was to assess the correlation between intracranial pressure and skull vibration measured on the promontory for stimulation to different sites on the head.Methods:Measurements were performed on four human cadaver heads. A bone conduction hearing aid was held in place with a 5-Newton steel headband at four locations (mastoid, forehead, eye, and neck). While stimulating in the frequency range of 0.3 to 10kHz, acceleration of the cochlear promontory was measured with a Laser Doppler Vibrometer, and intracranial pressure at the center of the head with a hydrophone.Results:Promontory acceleration and intracranial pressure was measurable for all stimulation sites. The ratios were comparable between all stimulation sites for frequencies below 2kHz.Conclusion:These findings indicate that both promontory acceleration and intracranial pressure are involved for stimulation on the sites investigated. The transmission pathway of sound energy is comparable for the four stimulation sites.

  • 17.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Model predictions for bone conduction perception in the human2016In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, no 15, p. 30076-30079Article in journal (Refereed)
    Abstract [en]

    Five different pathways are often suggested as important for bone conducted (BC) sound: (1) sound pressure in the ear canal, (2) inertia of the middle ear ossicles, (3) inertia of the inner ear fluid, (4) compression of the inner ear space, and (5) pressure transmission from the skull interior. The relative importance of these pathways was investigated with an acoustic-impedance model of the inner ear. The model incorporated data of BC generated ear canal sound pressure, middle ear ossicle motion, cochlear promontory vibration, and intracranial sound pressure. With BC stimulation at the mastoid, the inner ear inertia dominated the excitation of the cochlea but inner ear compression and middle ear inertia were within 10 dB for almost the entire frequency range of 0.1-10 kHz. Ear canal sound pressure gave little contribution at the low and high frequencies, but was around 15 dB below the total contribution at the mid frequencies. Intracranial sound pressure gave responses similar to the others at low frequencies, but decreased with frequency to a level of 55 dB below the total contribution at 10 kHz. When the BC inner ear model was evaluated against AC stimulation at threshold levels, the results were close up to approximately 4 kHz but deviated significantly at higher frequencies.

  • 18.
    Rudner, Mary
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Mishra, Sushmit
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, The Swedish Institute for Disability Research.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Snekkersten, Oticon A/S, Eriksholm Research Centre.
    Rönnberg, Jerker
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Linnaeus Centre HEAD.
    Seeing the talker’s face improves free recall of speech for young adults with normal hearing but not older adults with hearing loss2016In: Journal of Speech, Language and Hearing Research, ISSN 1092-4388, E-ISSN 1558-9102, Vol. 59, p. 590-599Article in journal (Refereed)
    Abstract [en]

    Purpose Seeing the talker's face improves speech understanding in noise, possibly releasing resources for cognitive processing. We investigated whether it improves free recall of spoken two-digit numbers.

    Method Twenty younger adults with normal hearing and 24 older adults with hearing loss listened to and subsequently recalled lists of 13 two-digit numbers, with alternating male and female talkers. Lists were presented in quiet as well as in stationary and speech-like noise at a signal-to-noise ratio giving approximately 90% intelligibility. Amplification compensated for loss of audibility.

    Results Seeing the talker's face improved free recall performance for the younger but not the older group. Poorer performance in background noise was contingent on individual differences in working memory capacity. The effect of seeing the talker's face did not differ in quiet and noise.

    Conclusions We have argued that the absence of an effect of seeing the talker's face for older adults with hearing loss may be due to modulation of audiovisual integration mechanisms caused by an interaction between task demands and participant characteristics. In particular, we suggest that executive task demands and interindividual executive skills may play a key role in determining the benefit of seeing the talker's face during a speech-based cognitive task

  • 19.
    Bernstein, Joshua G. W.
    et al.
    Walter Reed National Mil Medical Centre, MD 20889 USA.
    Danielsson, Henrik
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Hällgren, Mathias
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Rönnberg, Jerker
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Oticon AS, Denmark.
    Spectrotemporal Modulation Sensitivity as a Predictor of Speech-Reception Performance in Noise With Hearing Aids2016In: TRENDS IN HEARING, ISSN 2331-2165, Vol. 20, article id 2331216516670387Article in journal (Refereed)
    Abstract [en]

    The audiogram predicts amp;lt;30% of the variance in speech-reception thresholds (SRTs) for hearing-impaired (HI) listeners fitted with individualized frequency-dependent gain. The remaining variance could reflect suprathreshold distortion in the auditory pathways or nonauditory factors such as cognitive processing. The relationship between a measure of suprathreshold auditory function-spectrotemporal modulation (STM) sensitivity-and SRTs in noise was examined for 154 HI listeners fitted with individualized frequency-specific gain. SRTs were measured for 65-dB SPL sentences presented in speech-weighted noise or four-talker babble to an individually programmed master hearing aid, with the output of an ear-simulating coupler played through insert earphones. Modulation-depth detection thresholds were measured over headphones for STM (2cycles/octave density, 4-Hz rate) applied to an 85-dB SPL, 2-kHz lowpass-filtered pink-noise carrier. SRTs were correlated with both the high-frequency (2-6 kHz) pure-tone average (HFA; R-2 = .31) and STM sensitivity (R-2 = .28). Combined with the HFA, STM sensitivity significantly improved the SRT prediction (Delta R-2 = .13; total R-2 = .44). The remaining unaccounted variance might be attributable to variability in cognitive function and other dimensions of suprathreshold distortion. STM sensitivity was most critical in predicting SRTs for listenersamp;lt;65 years old or with HFA amp;lt;53 dB HL. Results are discussed in the context of previous work suggesting that STM sensitivity for low rates and low-frequency carriers is impaired by a reduced ability to use temporal fine-structure information to detect dynamic spectra. STM detection is a fast test of suprathreshold auditory function for frequencies amp;lt;2 kHz that complements the HFA to predict variability in hearing-aid outcomes for speech perception in noise.

  • 20.
    Chang, You
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Kim, Namkeun
    Incheon National University, South Korea.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    The development of a whole-head human finite-element model for simulation of the transmission of bone-conducted sound2016In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 140, no 3, p. 1635-1651Article in journal (Refereed)
    Abstract [en]

    A whole head finite element model for simulation of bone conducted (BC) sound transmission was developed. The geometry and structures were identified from cryosectional images of a female human head and eight different components were included in the model: cerebrospinal fluid, brain, three layers of bone, soft tissue, eye, and cartilage. The skull bone was modeled as a sandwich structure with an inner and outer layer of cortical bone and soft spongy bone (diploe) in between. The behavior of the finite element model was validated against experimental data of mechanical point impedance, vibration of the cochlear promontories, and transcranial BC sound transmission. The experimental data were obtained in both cadaver heads and live humans. The simulations showed multiple low-frequency resonances where the first was caused by rotation of the head and the second was close in frequency to average resonances obtained in cadaver heads. At higher frequencies, the simulation results of the impedance were within one standard deviation of the average experimental data. The acceleration response at the cochlear promontory was overall lower for the simulations compared with experiments but the overall tendencies were similar. Even if the current model cannot predict results in a specific individual, it can be used for understanding the characteristic of BC sound transmission in general. (C) 2016 Acoustical Society of America.

  • 21.
    Asp, Filip
    et al.
    Karolinska Institute, Sweden; Karolinska University Hospital, Sweden.
    Mäki-Torkko, Elina
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Karltorp, Eva
    Karolinska Institute, Sweden; Karolinska University Hospital, Sweden.
    Harder, Henrik
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Hergils, Leif
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Eskilsson, Gunnar
    Karolinska University Hospital, Sweden.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    A longitudinal study of the bilateral benefit in children with bilateral cochlear implants2015In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 54, no 2, p. 77-88Article in journal (Refereed)
    Abstract [en]

    Objective: To study the development of the bilateral benefit in children using bilateral cochlear implants by measurements of speech recognition and sound localization. Design: Bilateral and unilateral speech recognition in quiet, in multi-source noise, and horizontal sound localization was measured at three occasions during a two-year period, without controlling for age or implant experience. Longitudinal and cross-sectional analyses were performed. Results were compared to cross-sectional data from children with normal hearing. Study sample: Seventy-eight children aged 5.1-11.9 years, with a mean bilateral cochlear implant experience of 3.3 years and a mean age of 7.8 years, at inclusion in the study. Thirty children with normal hearing aged 4.8-9.0 years provided normative data. Results: For children with cochlear implants, bilateral and unilateral speech recognition in quiet was comparable whereas a bilateral benefit for speech recognition in noise and sound localization was found at all three test occasions. Absolute performance was lower than in children with normal hearing. Early bilateral implantation facilitated sound localization. Conclusions: A bilateral benefit for speech recognition in noise and sound localization continues to exist over time for children with bilateral cochlear implants, but no relative improvement is found after three years of bilateral cochlear implant experience.

  • 22.
    Kim, Nam Keun
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    A Possible Third Window for Bone Conducted Hearing: Cochlear Aqueduct vs. Vestibular Aqueduct2015In: Mechanics of hearing: Protein to perception, American Institute of Physics (AIP), 2015, Vol. 1703, no 060016, p. 060016-1-060016-4Conference paper (Refereed)
    Abstract [en]

    A third window, which is another cochlear fluid pathway different from the oval window and round window, is considered to be a significant factor in bone-conducted hearing. A three-dimensional finite element model of the human ear consisting of the middle ear and cochlea was used to investigate the effect of the third windows on bone-conducted heraing. This study is aimed to find the third window which causes the consistent cochlear responses with previous studies in air-conducted hearing, and causes the asymmetry of the volume velocity ratio between the oval window and round window in bone-conducted hearing. The preliminary result shows that the cochlear aqueduct and the vestibular aqueduct with high impedance do not affect the basilar membrane velocity in air-conducted hearing. On the contrary, in bone-conducted hearing, the direction of the shaking structure for the bone-conducted stimulation as well as the third window can be a significant factor causing the asymmetry of the volume velocity ratio found by Stenfelt et al.

  • 23.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Cochlear Boundary Motion During Bone Conduction Stimulation: Implications for Inertial and Compressional Excitation of the Cochlea2015In: MECHANICS OF HEARING: PROTEIN TO PERCEPTION, AMER INST PHYSICS , 2015, Vol. 1703, no 060005Conference paper (Refereed)
    Abstract [en]

    It is well accepted that the perception of bone conducted (BC) sound in the human relies on multiple pathways. Of these pathways, the inertial forces in the cochlear fluid and compression and expansion of the cochlear space have been suggested to be the most important. However, the frequency ranges where these two pathways dominate have not been clarified. This was investigated here using a box-model of the inner ear to estimate wall motion for a one-dimensional BC longitudinal skull vibration. Based on the dimensions of the inner ear and a BC wave speed of 400 m/s, the magnitude of the inertial motion of the cochlea was almost identical to the magnitude of the BC excitation except at the highest frequencies investigated (10 kHz). The compression (differential motion) was almost 100 times smaller than the inertial motion at 100 Hz but increased with frequency and at 5.9 kHz and above, the compression motion was greater than the inertial motion of the cochlea. This data was further analyzed in an impedance model of the cochlea and vestibule where the cochlear fluid, basilar membrane, oval window, round window, and cochlear and vestibular aqueducts were represented by acoustical impedances. That analysis showed that for a normal cochlea, the inertial excitation dominates the basilar membrane excitation for the whole frequency range investigated (0.1 to 10 kHz). However, when the oval window was immobilized simulating otosclerosis, the inertial effect diminished and the compressional excitation mode improved resulting in a dominant excitation from the compression of the cochlea at frequencies of 1.2 kHz and above. Also, the simulated BC hearing losses with otosclerosis according to this model were almost identical to the proposed Carharts notch seen clinically.

  • 24.
    Petersen, Eline B
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research. Eriksholm Research Centre, Snekkersten, Denmark, .
    Wöstmann, Malte
    International Max Planck Research School on Neuroscience of Communication, Leipzig, Germany, Max Planck Research Group “Auditory Cognition”, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
    Obleser, Jonas
    Max Planck Research Group “Auditory Cognition”, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
    Stenfelt, Stefan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Eriksholm Research Centre, Snekkersten, Denmark.
    Hearing loss impacts neural alpha oscillations under adverse listening conditions2015In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 6, no 177Article in journal (Refereed)
    Abstract [en]

    Degradations in external, acoustic stimulation have long been suspected to increase the load on working memory (WM). One neural signature of WM load is enhanced power of alpha oscillations (6–12 Hz). However, it is unknown to what extent common internal, auditory degradation, that is, hearing impairment, affects the neural mechanisms of WM when audibility has been ensured via amplification. Using an adapted auditory Sternberg paradigm, we varied the orthogonal factors memory load and background noise level, while the electroencephalogram was recorded. In each trial, participants were presented with 2, 4, or 6 spoken digits embedded in one of three different levels of background noise. After a stimulus-free delay interval, participants indicated whether a probe digit had appeared in the sequence of digits. Participants were healthy older adults (62–86 years), with normal to moderately impaired hearing. Importantly, the background noise levels were individually adjusted and participants were wearing hearing aids to equalize audibility across participants. Irrespective of hearing loss (HL), behavioral performance improved with lower memory load and also with lower levels of background noise. Interestingly, the alpha power in the stimulus-free delay interval was dependent on the interplay between task demands (memory load and noise level) and HL; while alpha power increased with HL during low and intermediate levels of memory load and background noise, it dropped for participants with the relatively most severe HL under the highest memory load and background noise level. These findings suggest that adaptive neural mechanisms for coping with adverse listening conditions break down for higher degrees of HL, even when adequate hearing aid amplification is in place.

  • 25.
    Saremi, Amin
    et al.
    Carl von Ossietzky University of Oldenburg, Germany.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Verhulst, Sarah
    Carl von Ossietzky University of Oldenburg, Germany; Carl von Ossietzky University of Oldenburg, Germany.
    How Do the Medial Olivocochlear Efferents Influence the Biomechanics of the Outer Hair Cells and Thereby the Cochlear Amplifier? Simulation Results2015In: MECHANICS OF HEARING: PROTEIN TO PERCEPTION, AMER INST PHYSICS , 2015, Vol. 1703, no 090030Conference paper (Refereed)
    Abstract [en]

    The bottom-up signal pathway, which starts from the outer ear and leads to the brain cortices, gives the classic image of the human sound perception. However, there have been growing evidences in the last six decades for existence of a functional descending network whereby the central auditory system can modulate the early auditory processing, in a top-down manner. The medial olivocochlear efferent fibers project from the superior olivary complex at the brainstem into the inner ear. They are linked to the basal poles of the hair cells by forming synaptic cisterns. This descending network can activate nicotinic cholinergic receptors (nAChR) that increase the membrane conductance of the outer hair cells and thereby modify the magnitude of the active force generated inside the cochlea. The aim of the presented work is to quantitatively investigate how the changes in the biomechanics of the outer hair cells, caused by the efferent activation, manipulate the cochlear responses. This is done by means of a frequency-domain biophysical model of the cochlea [ 12] where the parameters of the model convey physiological interpretations of the human cochlear structures. The simulations manifest that a doubling of the outer hair cell conductance, due to efferent activation, leads to a frequency-dependent gain reduction along the cochlear duct with its highest effect at frequencies between 1 kHz and 3.5 kHz and a maximum of approximately 10 dB gain reduction at 2 kHz. This amount of the gain inhibition and its frequency dependence reasonably agrees with the experimental data recorded from guinea pig, cat and human cochleae where the medial olivococlear efferents had been elicited by broad-band stimuli. The simulations also indicate that the efferent-induced increase of the outer hair cell conductance increases the best frequency of the cochlear responses, in the basal region. The presented simulations quantitatively confirm that activation of the medial olivocochlear efferents can biomechanically manipulate the cochlear responses, in a top-down manner, by inhibiting the gain of the cochlear amplifier as well as altering the frequency-position map (tuning pattern) of the cochlea.

  • 26.
    Petersen, Eline Borch
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Snekkersten, Eriksholm Research Centre, Denmark.
    Wöstmann, Malte
    University of Lübeck, Auditory Cognition.
    Obleser, Jonas
    University of Lübeck, Auditory Cognition.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Snekkersten, Oticon A/S, Eriksholm Research Centre.
    Influence of hearing impairment on alpha power during retention of auditory stimuli2015Conference paper (Other academic)
  • 27.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Inner ear contribution to bone conduction hearing in the human2015In: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 329, p. 41-51Article, review/survey (Refereed)
    Abstract [en]

    Bone conduction (BC) hearing relies on sound vibration transmission in the skull bone. Several clinical findings indicate that in the human, the skull vibration of the inner ear dominates the response for BC sound. Two phenomena transform the vibrations of the skull surrounding the inner ear to an excitation of the basilar membrane, (1) inertia of the inner ear fluid and (2) compression and expansion of the inner ear space. The relative importance of these two contributors were investigated using an impedance lumped element model. By dividing the motion of the inner ear boundary in common and differential motion it was found that the common motion dominated at frequencies below 7 kHz but above this frequency differential motion was greatest. When these motions were used to excite the model it was found that for the normal ear, the fluid inertia response was up to 20 dB greater than the compression response. This changed in the pathological ear where, for example, otosclerosis of the stapes depressed the fluid inertia response and improved the compression response so that inner ear compression dominated BC hearing at frequencies above 400 Hz. The model was also able to predict experimental and clinical findings of BC sensitivity in the literature, for example the so called Carhart notch in otosclerosis, increased BC sensitivity in superior semicircular canal dehiscence, and altered BC sensitivity following a vestibular fenestration and RW atresia. (C) 2014 Elsevier B.V. All rights reserved.

  • 28.
    Chang, You
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Kim, Nam Keun
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Simulation of Bone-Conducted Sound Transmission in a Three-Dimensional Finite-Element Model of a Human Skull2015In: MECHANICS OF HEARING: PROTEIN TO PERCEPTION, AMER INST PHYSICS , 2015, Vol. 1703, no 060014Conference paper (Refereed)
    Abstract [en]

    Bone conduction (BC) is the transmission of sound to the inner ear through the bones of the skull. This type of transmission is used in humans fitted with BC hearing aids as well as to classify between conductive and sensorineural hearing losses. The objective of the present study is to develop a finite-element (FE) model of the human skull based on cryosectional images of a female cadaver head in order to gain better understanding of the sound transmission. Further, the BC behavior was validated in terms of sound transmission against experimental data published in the literature. Results showed the responses of the simulated skull FE model were consistent with the experimentally reported data.

  • 29.
    Petersen, Eline Borch
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Snekkersten, Eriksholm Research Centre.
    Wöstmann, Malte
    University of Lübeck, Auditory Cognition.
    Obleser, Jonas
    University of Lübeck, Auditory Cognition.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Snekkersten, Oticon A/S, Eriksholm Research Centre.
    Tuning in on the target: The influence of hearing impairment on the neural encoding of speech2015Conference paper (Other academic)
  • 30.
    Kim, Namkeun
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Chang, You
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    A Three-Dimensional Finite-Element Model of a Human Dry Skull for Bone-Conduction Hearing2014In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2014, no 519429Article in journal (Refereed)
    Abstract [en]

    A three-dimensional finite-element (FE) model of a human dry skull was devised for simulation of human bone-conduction (BC) hearing. Although a dry skull is a simplification of the real complex human skull, such model is valuable for understanding basic BC hearing processes. For validation of the model, the mechanical point impedance of the skull as well as the acceleration of the ipsilateral and contralateral cochlear bone was computed and compared to experimental results. Simulation results showed reasonable consistency between the mechanical point impedance and the experimental measurements when Youngs modulus for skull and polyurethane was set to be 7.3 GPa and 1 MPa with 0.01 and 0.1 loss factors at 1 kHz, respectively. Moreover, the acceleration in the medial-lateral direction showed the best correspondence with the published experimental data, whereas the acceleration in the inferior-superior direction showed the largest discrepancy. However, the results were reasonable considering that different geometries were used for the 3D FE skull and the skull used in the published experimental study. The dry skull model is a first step for understanding BC hearing mechanism in a human head and simulation results can be used to predict vibration pattern of the bone surrounding the middle and inner ear during BC stimulation.

  • 31.
    Rönnberg, Niklas
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Rudner, Mary
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Lunner, Thomas
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Eriksholm Research Centre, Oticon A/S, Snekkersten.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Assessing listening effort by measuring short-term memory storage and processing of speech in noise2014In: Speech, Language and Hearing, ISSN 2050-5728, Vol. 17, no 3, p. 123-132Article in journal (Refereed)
    Abstract [en]

    Objective

    The aim of this study was to investigate the effect of working memory capacity (WMC) and updating ability (UA) on listening effort measured using a new test, the Auditory Inference Span Test (AIST), as an objective measure of listening effort.

    Design

    The AIST is based on Swedish five-word sentences and taps into three memory load levels (MLLs). It was administered in stationary speech-shaped noise at −2, −4, and −6 dB signal-to-noise ratio (SNR). WMC was assessed using the reading span test, and UA was assessed using the letter memory test. We also collected data on speech-in-noise performance and subjectively rated listening effort at the three SNRs.

    Study sample

    Thirty-nine participants with normal hearing thresholds (≤20 dB HL for 250 to 4000 Hz) took part in the study.

    Results

    AIST performance decreased with increasing MLL and was related to WMC and UA. Participants with high WMC performed better than those with low WMC at more favorable SNRs. Participants with high UA performed better than participants with low UA at the intermediate MLL, which made particular demands on the UA. Neither speech recognition scores nor subjectively rated listening effort was associated with AIST performance or either of the cognitive variables.

    Conclusion

    AIST taps into cognitive functions necessary for understanding speech in noise. However, in its current form AIST may be too cognitively taxing to successfully measure graded listening effort in participants with lower cognitive capacity.

  • 32.
    Saremi, Amin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Mäki-Torkko, Elina
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Changes in Temporal and Spectral Functions of the Auditory Periphery Due to Aging and Noise-induced Cochlear Pathologies: A Comparative Clinical Study2014Manuscript (preprint) (Other academic)
    Abstract [en]

    Objective: This study includes a battery of psychoacoustical and electrophysiological tests to quantitatively investigate the changes in the frequency and the temporal features of the human auditory periphery caused by aging (presbyacusis) and noise-induced lesions, two common types of sensorineural hearing impairments. The scores are comparatively analyzed.

    Design: These clinical experiments have been implemented in MATLAB software.

    Study sample: 20 normal hearing adults (aged 30-54), 20 older hearing-impaired subjects (aged 65-70) with no history of Ototoxic medication or noise exposure and 7 adult men with a traceable noise-induced hearing impairment.

    Results: The observed temporal and spectral declines are generally consistent with the high-frequency audiometric loss depicted by the audiogram, for each group. Moreover, the test battery provides valuable information on the frequency sensitivity, temporal resolution, loudness growth, compression and otoacoustic emissions.

    Conclusion: These scores are compared with the predictions of a physiologicallybased cochlear model to provide evidence about specific inner-ear pathologies, beyond what the audiogram can indicate. Among these 7 clinical experiments, the results from the forward temporal masking test, the categorical loudness discrimination test and the distortion product otoacoustic emission test provide the most differential information about the underlying cellular lesions. The results indicate that the reduction in the temporal resolution is substantially age-relate since the presbyacusis listeners, unlike the other groups, obtained almost no benefit from the temporal cues provided by the gap duration at any of the experiments. Moreover, the results suggest that the DPOAEs reflect the cellular lesions associated with the acoustic overstimulation rather than the age-related strial degenerations.

  • 33.
    Mishra, Sushmit
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. 3Eriksholm Research Centre, Oticon A/S, Snekkersten, Denmark.
    Rönnberg, Jerker
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Rudner, Mary
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Cognitive spare capacity in older adults with hearing loss2014In: Frontiers in Aging Neuroscience, ISSN 1663-4365, E-ISSN 1663-4365, Vol. 6, no 96Article in journal (Refereed)
    Abstract [en]

    Individual differences in working memory capacity (WMC) are associated with speech recognition in adverse conditions, reflecting the need to maintain and process speech fragments until lexical access can be achieved. When working memory resources are engaged in unlocking the lexicon, there is less Cognitive Spare Capacity (CSC) available for higher level processing of speech. CSC is essential for interpreting the linguistic content of speech input and preparing an appropriate response, that is, engaging in conversation. Previously, we showed, using a Cognitive Spare Capacity Test (CSCT) that in young adults with normal hearing, CSC was not generally related to WMC and that when CSC decreased in noise it could be restored by visual cues. In the present study, we investigated CSC in 24 older adults with age-related hearing loss, by administering the CSCT and a battery of cognitive tests. We found generally reduced CSC in older adults with hearing loss compared to the younger group in our previous study, probably because they had poorer cognitive skills and deployed them differently. Importantly, CSC was not reduced in the older group when listening conditions were optimal. Visual cues improved CSC more for this group than for the younger group in our previous study. CSC of older adults with hearing loss was not generally related to WMC but it was consistently related to episodic long term memory, suggesting that the efficiency of this processing bottleneck is important for executive processing of speech in this group.

  • 34. Borch Petersen, E
    et al.
    Wöstmann, M
    Obleser, J
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research. Eriksholm Research Centre, Snekkersten, Denmark.
    Compensated hearing loss predicts generation of auditory evoked potentials.2014Conference paper (Refereed)
  • 35.
    Saremi, Amin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Effects of Acoustic Overstimulation and the Associated Cellular Lesions on the Cochlear Amplifier: Simulation Results2014Manuscript (preprint) (Other academic)
    Abstract [en]

    A physiologically-based electromechanical model of the human cochlea is used in this study to explicitly simulate the effects of acoustical overstimulation, and the associated cellular deficiencies, on the gain of the cochlear amplifier. The simulations demonstrate that as the micromechanics of the stereocillia transduction channels is altered due to the traumatic acoustical overstimulation, the compressive/nonlinear behavior of the cochlear amplifier is significantly modified. When the loudness growth is estimated by the integral of the cochlear amplification with respect to the sound intensity, these modifications lead to an impaired loudness function reminiscent of the recruitment phenomenon. Furthermore, when a severe noise-induced loss of outer hair cells is assumed at basal regions of the cochlea, the model predicts a mild loss at lower frequencies followed by a steeply sloping notch-like amplification loss of approximately 80 dB around 4.5 kHz. This prediction is reasonably in line with the threshold elevations observed clinically from the noise-damaged human ears. Moreover, the results quantitatively demonstrate that the center frequency, the width and the depth of the amplification loss are directly determined by the severity and the location of the outer hair cell loss along the cochlear duct.

  • 36.
    Rönnberg, Niklas
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linköping University, The Swedish Institute for Disability Research.
    Rudner, Mary
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. Oticon Research Centre Eriksholm, Denmark.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Memory performance on the Auditory Inference Span Test is independent of background noise type for young adults with normal hearing at high speech intelligibility2014In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 5, no 1490Article in journal (Refereed)
    Abstract [en]

    Listening in noise is often perceived to be effortful. This is partly because cognitive resources are engaged in separating the target signal from background noise, leaving fewer resources for storage and processing of the content of the message in working memory. The Auditory Inference Span Test (AIST) is designed to assess listening effort by measuring the ability to maintain and process heard information. The aim of this study was to use AIST to investigate the effect of background noise types and signal-to-noise ratio (SNR) on listening effort, as a function of working memory capacity (WMC) and updating ability (UA). The AIST was administered in three types of background noise: steady-state speech-shaped noise, amplitude modulated speech-shaped noise, and unintelligible speech. Three SNRs targeting 90% speech intelligibility or better were used in each of the three noise types, giving nine different conditions. The reading span test assessed VVMC, while UA was assessed with the letter memory test. Twenty young adults with normal hearing participated in the study. Results showed that AIST performance was not influenced by noise type at the same intelligibility level, but became worse with worse SNR when background noise was speech-like. Performance on AIST also decreased with increasing memory load level. Correlations between AIST performance and the cognitive measurements suggested that WMC is of more importance for listening when SNRs are worse, while UA is of more importance for listening in easier SNRs. The results indicated that in young adults with normal hearing, the effort involved in listening in noise at high intelligibility levels is independent of the noise type. However, when noise is speech-like and intelligibility decreases, listening effort increases, probably due to extra demands on cognitive resources added by the informational masking created by the speech fragments and vocal sounds in the background noise.

  • 37.
    Skagerstrand, Asa
    et al.
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research. University of Örebro, Sweden.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Arlinger, Stig
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Wikstrom, Joel
    University of Örebro, Sweden .
    Sounds perceived as annoying by hearing-aid users in their daily soundscape2014In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 53, no 4, p. 259-269Article in journal (Refereed)
    Abstract [en]

    Background: The noises in modern soundscapes continue to increase and are a major origin for annoyance. For a hearing-impaired person, a hearing aid is often beneficial, but noise and annoying sounds can result in non-use of the hearing aid, temporary or permanently. Objective: The purpose of this study was to identify annoying sounds in a daily soundscape for hearing-aid users. Design: A diary was used to collect data where the participants answered four questions per day about annoying sounds in the daily soundscape over a two-week period. Study sample: Sixty adult hearing-aid users. Results: Of the 60 participants 91% experienced annoying sounds daily when using hearing aids. The annoying sound mentioned by most users, was verbal human sounds, followed by other daily sound sources categorized into 17 groups such as TV/radio, vehicles, and machine tools. When the hearing-aid users were grouped in relation to age, hearing loss, gender, hearing-aid experience, and type of signal processing used in their hearing aids, small and only few significant differences were found when comparing their experience of annoying sounds. Conclusions: The results indicate that hearing-aid users often experience annoying sounds and improved clinical fitting routines may reduce the problem.

  • 38.
    Bernstein, Joshua G
    et al.
    National Military Audiology and Speech Pathology Center Walter Reed National Military Medical Center, Bethesda, MD, USA.
    Danielsson, Henrik
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Hällgren, Mathias
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linnaeus Centre HEAD.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Rönnberg, Jerker
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Lunner, Thomas
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Spectrotemporal modulation sensitivity as a predictor of speech intelligibility in noise with hearing aids2014In: Spectrotemporal modulation sensitivity as a predictor of speech intelligibility in noise with hearing aids, 2014Conference paper (Refereed)
    Abstract [en]

    The audiogram predicts less than a third of the variance in speech reception thresholds (SRTs) for hearing-impaired (HI) listeners properly fit with individualized frequency-dependent gain. The remaining variance is often attributed to a combination of su-prathreshold distortion in the auditory pathway and non-auditory factors such as cogni-tive processing. Distinguishing between these factors requires a measure of suprathresh-old auditory processing to account for the non-cognitive contributions. Preliminary re-sults in 12 HI listeners identified a correlation between spectrotemporal modulation (STM) sensitivity and speech intelligibility in noise presented over headphones. The cur-IHCON 2014 27 August 13-17, 2014rent study assessed the effectiveness of STM sensitivity as a measure of suprathreshold auditory function to predict free-field SRTs in noise for a larger group of 47 HI listeners with hearing aids.SRTs were measured for Hagerman sentences presented at 65 dB SPL in stationary speech-weighted noise or four-talker babble. Pre-recorded speech and masker stimuli were played through a small anechoic chamber equipped with a master hearing aid pro-grammed with individualized gain. The output from an IEC711 Ear Simulator was played binaurally through insert earphones. Three processing algorithms were examined: linear gain, linear gain plus noise reduction, or fast-acting compressive gain.STM stimuli consist of spectrally-rippled noise with spectral-peak frequencies that shift over time. STM with a 2-cycle/octave spectral-ripple density and a 4-Hz modulation rate was applied to a 2-kHz lowpass-filtered pink-noise carrier. Stimuli were presented over headphones at 80 dB SPL (±5-dB roving). The threshold modulation depth was estimated adaptively in a two-alternative forced-choice task.STM sensitivity was strongly correlated (R2=0.48) with the global SRT (i.e., the SRTs averaged across masker and processing conditions). The high-frequency pure-tone aver-age (3-8 kHz) and age together accounted for 23% of the variance in global SRT. STM sensitivity accounted for an additional 28% of the variance in global SRT (total R2=0.51) when combined with these two other metrics in a multiple-regression analysis. Correla-tions between STM sensitivity and SRTs for individual conditions were weaker for noise reduction than for the other algorithms, and marginally stronger for babble than for sta-tionary noise.The results are discussed in the context of previous work suggesting that STM sensitivity for low rates and low carrier frequencies is impaired by a reduced ability to use temporal fine-structure information to detect slowly shifting spectral peaks. STM detection is a fast, simple test of suprathreshold auditory function that accounts for a substantial pro-portion of variability in hearing-aid outcomes for speech perception in noise.

  • 39.
    Thodi, Chryssola
    et al.
    European University Cyprus, Nicosia.
    Parazzini, M.
    Istituto di Ingegneria Biomedica, Milano, Italy.
    Kramer, Sophia
    VU University Medical Center, Amsterdam, The Netherlands.
    Davis, Adrian
    Royal Free London NHS Foundation Trust, London, UK.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Janssen, Thomas
    Technische Universitaet Muenchen, Germany.
    Smith, Pauline
    Royal Free London NHS Foundation Trust, London, UK.
    Stevens, Dye
    Cardiff University, Wales, UK.
    Pronk, Marieke
    VU University Medical Center, Amsterdam, The Netherlands.
    Anteunis, L. I.
    University Medical Centre, Maastricht, The Netherlands .
    Schirkonyer, Volker
    Technische Universitaet Muenchen, Germany.
    Grandori, Ferdinando
    Istituto di Ingegneria Biomedica, Milano, Italy.
    Adult Hearing Screening: Follow-Up and Outcomes2013In: American Journal of Audiology, ISSN 1059-0889, E-ISSN 1558-9137, Vol. 22, p. 183-185Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To screen hearing and evaluate outcomes in community-dwelling older adults.

    METHOD:

    Three thousand and twenty-five adults responded to an invitation to be screened by questionnaire, otoscopy, and pure-tone audiometry. Pure-tone average (PTA) >35 dB HL in the worse ear, unilateral hearing loss, or otoscopic findings were the criteria for referral for services. A questionnaire related to compliance with referral recommendations was completed by telephone interview for 160 randomly selected participants after 1-2 years from referral.

    RESULTS:

    The referral rate for audiologic/hearing aid evaluation was 46%, and referral for cerumen removal/medical evaluation was 17%. Of the people referred for audiologic/hearing aid evaluation, 18% tried a hearing aid; 2 years later, 11% were using a hearing aid. Screening recommendations affected participants' decision to seek help. Study participants stated that the screening was helpful, it should be offered to everybody, and they would participate in future screenings.

    CONCLUSION:

    Although adult hearing screening offered timely identification of hearing loss for adults seeking help, follow-up with hearing aid treatment was low.

  • 40.
    Rudner, Mary
    et al.
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Mishra, Sushmit
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Stenfelt, Stefan
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Lunner, Thomas
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine. Eriksholm Research Centre, Snekkersten, Denmark.
    Rönnberg, Jerker
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Age-related individual differences in working memory capacity and executive ability influence cognitive spare capacity2013Conference paper (Refereed)
  • 41.
    Mishra, Sushmit
    et al.
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Stenfelt, Stefan
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine.
    Lunner, Thomas
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Clinical and Experimental Medicine. Eriksholm Research Centre, Snekkersten, Denmark.
    Rönnberg, Jerker
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Rudner, Mary
    Linköping University, The Swedish Institute for Disability Research. Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences.
    Age-related sensory and cognitive decline make it harder to remember speech in noise across serial positions2013Conference paper (Other academic)
  • 42.
    Neely, Stephen
    et al.
    Boys Town National Research Hospital, Omaha, Nebraska, USA.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Schairer, Kim
    Quillen Veterans Affairs Medical Center, Mountain Home, Tennessee, USA.
    Alternative ear-canal measures related to absorbance2013In: Ear and Hearing, ISSN 0196-0202, E-ISSN 1538-4667, Vol. 34, no Supplement 1, p. 72s-77sArticle in journal (Refereed)
    Abstract [en]

    Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1) sound intensity level, (2) forward pressure level, (3) time-domain ear-canal reflectance, and (4) cochlear reflectance. These four related measures are similar to absorbance in their utilization of wideband stimuli and their focus on recording ear-canal sound pressure. The related measures differ from absorbance in how the ear-canal pressure is analyzed and in the type of information that is extracted from the recorded response. Sound intensity level and forward pressure level have both been shown to be better as measures of sound level in the ear canal compared with sound pressure level because they reduced calibration errors due to standing waves in studies of behavioral thresholds and otoacoustic emissions. Time-domain ear-canal reflectance may be used to estimate ear-canal geometry and may have the potential to assess middle ear pathology. Cochlear reflectance reveals information about the inner ear that is similar to what is provided by other types of otoacoustic emissions, and may have theoretical advantages that strengthen its interpretation.

  • 43.
    Rosowski, John
    et al.
    Harvard Medical School, Boston, Massachusetts, USA.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Lilly, David
    Portland Veterans Affairs Medical Center, Portland, Oregon, USA.
    An overview of wideband immittance measurements techniques and terminology: you say absorbance, I say reflectance2013In: Ear and Hearing, ISSN 0196-0202, E-ISSN 1538-4667, Vol. 34, no Supplement 1, p. 9s-16sArticle in journal (Refereed)
    Abstract [en]

    This article reviews the relationships among different acoustic measurements of the mobility of the tympanic membrane, including impedance, admittance, reflectance, and absorbance, which the authors group under the rubric of immittance measures. Each of these quantities is defined and related to the others. The relationship is most easily grasped in terms of a straight rigid ear canal of uniform area terminated by a uniform middle ear immittance placed perpendicular to the long axis of the ear canal. Complications due to variations from this geometry are discussed. Different methods for measuring these quantities are described, and the assumptions inherent within each method are made explicit. The benefits of wideband measurements of these quantities are described, as are the benefits and limitations of different components of immittance and reflectance/absorbance. While power reflectance (the square of the magnitude of pressure reflectance) is relatively invariant along the length of the ear canal, it has the disadvantage that it ignores phase information that may be useful in assessing the presence of acoustic leaks in ear-canal measurements and identifying other potential error sources. A combination of reflectance and impedance magnitude and angle give a more complete description of the middle ear from measurements in the ear canal.

  • 44.
    Stenfelt, Stefan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Zeitooni, Mehrnaz
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Binaural hearing ability with mastoid applied bilateral bone conduction stimulation in normal hearing subjects2013In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 134, no 1, p. 481-493Article in journal (Refereed)
    Abstract [en]

    The ability to use binaural cues when stimulation was by bilaterally applied bone conduction (BC) transducers was investigated in 20 normal hearing participants. The results with BC stimulation were compared with normal air conduction (AC) stimulation through earphones. The binaural hearing ability was tested by spatial release from masking, binaural intelligibility level difference (BILD), binaural masking level difference (BMLD) using chirp stimulation, and test of the precedence effect. In all tests, the participants revealed a benefit of bilateral BC stimulation indicating use of binaural cues. In the speech based tests, the binaural benefit for BC stimulation was approximately half that with AC stimulation. For the BC BMLD test with chirp stimulation, there were indications of superposition of the ipsilateral and contralateral pathways at the cochlear level affecting the results. The precedence effect test indicated significantly worse results for BC stimulation than for AC stimulation with low-frequency stimulation while they were close for high-frequency stimulation; broad-band stimulation gave results that were slightly worse than the high-frequency results.

  • 45.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Binaural hearing with bone conduction stimulation – what is possible?2013Conference paper (Refereed)
  • 46.
    Zeitooni, Mehrnaz
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Mäki-Torkko, Elina
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Binaural hearing with bone conduction stimulation in normal hearing subjects2013Conference paper (Refereed)
  • 47.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Bredbandsmätning av mellanörat2013In: Audio-Nytt, ISSN 0347-6308, Vol. 40, no 1-2, p. 24-25Article in journal (Other (popular science, discussion, etc.))
  • 48.
    Feeney, Patrick
    et al.
    Oregon Health and Science University, Portland, Oregon, USA.
    Hunter, Lisa
    Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
    Kei, Joseph
    University of Queensland, Queensland, Australia.
    Lilly, David
    Oregon Health and Science University, Portland, Oregon, USA.
    Margolis, Robert
    University of Minnesota, Minneapolis, Minnesota, USA.
    Nakajima, Heidi
    Harvard Medical School, Boston, Massachusetts, USA.
    Neely, Stephen
    Boys Town National Research Hospital, Omaha, Nebraska, USA.
    Prieve, Beth
    Syracuse University, Syracuse, New York, USA.
    Rosowski, John
    Harvard Medical School, Boston, Massachusetts, USA.
    Sanford, Chris
    Idaho State University, Pocatello, Idaho, USA.
    Schairer, Kim
    James H. Quillen Veterans Affairs Medical Center, Mountain Home, Tennessee, USA.
    Shahnaz, Navid
    University of British Columbia, Vancouver, Canada.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Voss, Susan
    Smith College, Northampton, Massachusetts, USA.
    Consensus statement: Eriksholm workshop on wideband absorbance measures of the middle ear2013In: Ear and Hearing, ISSN 0196-0202, E-ISSN 1538-4667, Vol. 34, no Supplement 1, p. 78s-79sArticle in journal (Refereed)
    Abstract [en]

    The participants in the Eriksholm Workshop on Wideband Absorbance Measures of the Middle Ear developed statements for this consensus article on the final morning of the Workshop. The presentations of the first 2 days of the Workshop motivated the discussion on that day. The article is divided into three general areas: terminology; research needs; and clinical application.The varied terminology in the area was seen as potentially confusing, and there was consensus on adopting an organizational structure that grouped the family of measures into the term wideband acoustic immittance (WAI), and dropped the term transmittance in favor of absorbance. There is clearly still a need to conduct research on WAI measurements. Several areas of research were emphasized, including the establishment of a greater WAI normative database, especially developmental norms, and more data on a variety of disorders; increased research on the temporal aspects of WAI; and methods to ensure the validity of test data. The area of clinical application will require training of clinicians in WAI technology. The clinical implementation of WAI would be facilitated by developing feature detectors for various pathologies that, for example, might combine data across ear-canal pressures or probe frequencies.

  • 49.
    Röösli, Christof
    et al.
    University of Zurich.
    Sim, Jae-Hoon
    University of Zurich.
    Gehrig, R
    University of Zurich.
    Fausch, BC
    University of Zurich.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Huber, Alexander
    University of Zurich.
    Correlation between intracranial pressure and skull vibration in bone conduction of cadaveric human whole heads2013Conference paper (Refereed)
  • 50.
    Saremi, Amin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Stenfelt, Stefan
    Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology. Linköping University, Faculty of Health Sciences.
    Effect of metabolic presbyacusis on cochlear responses: A simulation approach using a physiologically-based model2013In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 134, no 4, p. 2833-2851Article in journal (Refereed)
    Abstract [en]

    In the presented model, electrical, acoustical, and mechanical elements of the cochlea are explicitly integrated into a signal transmission line where these elements convey physiological interpretations of the human cochlear structures. As a result, this physiologically-motivated model enables simulation of specific cochlear lesions such as presbyacusis. The hypothesis is that high-frequency hearing loss in older adults may be due to metabolic presbyacusis whereby age-related cellular/chemical degenerations in the lateral wall of the cochlea cause a reduction in the endocochlear potential. The simulations quantitatively confirm this hypothesis and emphasize that even if the outer and inner hair cells are totally active and intact, metabolic presbyacusis alone can significantly deteriorate the cochlear functionality. Specifically, in the model, as the endocochlear potential decreases, the transduction mechanism produces less receptor current such that there is a reduction in the battery of the somatic motor. This leads to a drastic decrease in cochlear amplification and frequency sensitivity, as well as changes in position-frequency map (tuning pattern) of the cochlea. In addition, the simulations show that the age-related reduction of the endocochlear potential significantly inhibits the firing rate of the auditory nerve which might contribute to the decline of temporal resolution in the aging auditory system.

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