liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
1 - 27 av 27
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Cros, Olivier
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Borga, Magnus
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Pauwels, Elin
    University of Ghent, Belgium.
    Dirckx, Joris J. J.
    University of Antwerp, Belgium.
    Gaihede, Michael
    Aalborg University Hospital, Denmark.
    Micro-channels in the mastoid anatomy. Indications of a separate blood supply of the air cell system mucosa by micro-CT scanning2013Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 301, s. 60-65Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mastoid air cell system has traditionally been considered to have a passive role in gas exchange and pressure regulation of the middle ear possibly with some acoustic function. However, more evidence has focused on the mucosa of the mastoid, which may play a more active role in regulation of middle ear pressure.

    In this study we have applied micro-CT scanning on a series of three human temporal bones. This approach greatly enhances the resolution (40–60 μm), so that we have discovered anatomical details, which has not been reported earlier. Thus, qualitative analysis using volume rendering has demonstrated notable micro-channels connecting the surface of the compact bone directly to the mastoid air cells as well as forming a network of connections between the air cells. Quantitative analysis on 2D slices was employed to determine the average diameter of these micro-channels (158 μm; range = 40–440 μm) as well as their density at a localized area (average = 75 cm−2; range = 64–97 cm−2).

    These channels are hypothesized to contain a separate vascular supply for the mastoid mucosa. However, future studies of the histological structure of the micro-channels are warranted to confirm the hypothesis. Studies on the mastoid mucosa and its blood supply may improve our knowledge of its physiological properties, which may have important implications for our understanding of the pressure regulation of the middle ear.

  • 2.
    Cros, Olivier
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Department of Otolaryngology, Head and Neck Surgery, Aalborg Hospital, Aarhus University Hospital, Denmark.
    Gaihede, Michael L.
    Department of Otolaryngology, Head and Neck Surgery, Aalborg Hospital, Aarhus University Hospital, Denmark.
    Borga, Magnus
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Mastoid structural properties determined by imaging analysis of high resolution CT-scanning2010Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 263, nr 1-2, s. 242-243Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hypothesis: The structure of the mastoid air cells can be described by quantitative imaging analysis of high-resolution CT-scans, which may contribute to understand its function in normal and pathological ears. Background: Negative middle ear pressure is a common factor in middle ear diseases resulting from an imbalance between mastoid gas exchange and Eustachian tube function. While the Eustachian tube function has been the main focus of research, more recent studies indicate that the mastoid may play an active role in pressure regulation. The mastoid structure with numerous air cells reflects a large area to volume ratio (AV-ratio) adapted to efficient gas exchange. Imaging analysis applied to high resolution CT-scanning can describe quantitative measures, which may reveal important information about mastoid function and its role in healthy and diseased ears. Materials and methods: Quantitative analysis was performed on a series of unselected high resolution CT-scans (voxel size: 0.29 _ 0.29 _ 0.625 mm) from 36 ears in 24 patients. Area and volume were determined using Cavalieri’s method, i.e. by summing cross-sectional areas. The AV-ratio was computed for each scan. Results: Mean area was 69 cm2 (range: 23–134cm2), mean volume was 4 cm3 (range: 1.3–10.8 cm3), and mean AV-ratio was 16 cm-1 (range: 11.2–21.0 cm-1). The area correlated linearly to the volume by A = 17.2*V-0.2. Conclusion: The area and volume values corresponded with previous studies, and the additional AV-ratio reflected the functional properties of the mastoid in terms of capability for gas exchange. Due to a series of similarities between structure and function of the lungs and mastoid, it seems likely to propose a tree-structure of dividing mastoid cells. In respiratory research, analysis describing the dimensions of series of bronchi generations has been applied, and based on current results; our aim of future research is to establish similar details of mastoid tree-structure. Funding source: Various private Danish funds.

  • 3.
    Cros, Olivier
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Department of Otolaryngology, Head and Neck Surgery, Aalborg University Hospital, Denmark.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Andersson, Mats
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Pawels, Elin
    Centre for X-ray Tomography, Department of Physics and Astronomy, University of Ghent, Belgium.
    Borga, Magnus
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Gaihede, Michael
    Department of Otolaryngology, Head and Neck Surgery, Aalborg University Hospital, Denmark / Department of Clinical Medicine, Aalborg University, Denmark.
    Determination of the mastoid surface area and volume based on micro-CT scanning of human temporal bone: Geometrical parameters dependence on scanning resolutions2016Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 340, s. 127-134Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mastoid air cell system (MACS) with its large complex of interconnected air cells reflects an enhanced surface area (SA) relative to its volume (V), which may indicate that the MACS is adapted to gas exchange and has a potential role in middle ear pressure regulation. Thus, these geometric parameters of the MACS have been studied by high resolution clinical CT scanning. However, the resolution of these scans is limited to a voxel size of around 0.6 mm in all dimensions, and so, the geometrical parameters are also limited. Small air cells may appear below the resolution and cannot be detected. Such air cells may contribute to a much higher SA than the V, and thus, also the SA/V ratio. More accurate parameters are important for analysis of the function of the MACS including physiological modeling.

    Our aim was to determine the SA, V, and SA/V ratio in MACS in human temporal bones at highest resolution by using micro-CT-scanning. Further, the influence of the resolution on these parameters was investigated by downsampling the data. Eight normally aerated temporal bones were scanned at the highest possible resolution (30-60 μm). The SA was determined using a triangular mesh fitted onto the segmented MACS. The V was determined by summing all the voxels containing air. Downsampling of the original data was applied four times by a factor of 2.

    The mean SA was 194 cm2, the mean V was 9 cm3, and the mean SA/V amounted to 22 cm-1. Decreasing the resolution resulted in a non-linear decrement of SA and SA/V, whereas V was mainly independent of the resolution.

    The current study found significantly higher SA and SA/V compared with previous studies using clinical CT scanning at lower resolutions. These findings indicate a separate role of the MACS compared with the tympanum, and the results are important for a more accurate modeling of the middle ear physiology.

  • 4.
    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
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Logopedi, Audiologi och Otorhinolaryngologi. Linköpings universitet, Medicinska fakulteten.
    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 stimulation2017Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 355Artikel i tidskrift (Refereegranskat)
    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.

  • 5.
    Eeg-Olofsson, Måns
    et al.
    Sahlgrenska University Hospital, Göteborg University, Sweden.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Taghavi, Hamidreza
    Chalmers University of Technology, Göteborg, Sweden.
    Reinfeldt, Sabine
    Chalmers University of Technology, Göteborg, Sweden.
    Håkansson, Bo
    Chalmers University of Technology, Göteborg, Sweden.
    Tengstrand, Tomas
    Sahlgrenska University Hospital, Göteborg, Sweden.
    Finizia, Chatarina
    Sahlgrenska University Hospital, Göteborg University, Sweden.
    Transmission of bone conducted sound – Correlation between hearing perception and cochlear vibration2013Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 306, s. 11-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The vibration velocity of the lateral semicircular canal and the cochlear promontory was measured on 16 subjects with a unilateral middle ear common cavity, using a laser Doppler vibrometer, when the stimulation was by bone conduction (BC). Four stimulation positions were used: three ipsilateral positions and one contralateral position. Masked BC pure tone thresholds were measured with the stimulation at the same four positions. Valid vibration data were obtained at frequencies between 0.3 and 5.0 kHz. Large intersubject variation of the results was found with both methods. The difference in cochlear velocity with BC stimulation at the four positions varied as a function of frequency while the tone thresholds showed a tendency of lower thresholds with stimulation at positions close to the cochlea. The correlation between the vibration velocities of the two measuring sites of the otic capsule was high. Also, relative median data showed similar trends for both vibration and threshold measurements. However, due to the high variability for both vibration and perceptual data, low correlation between the two methods was found at the individual level. The results from this study indicated that human hearing perception from BC sound can be estimated from the measure of cochlear vibrations of the otic capsule. It also showed that vibration measurements of the cochlea in cadaver heads are similar to that measured in live humans.

  • 6.
    Flock, Å.
    et al.
    Karolinska Institute, Stockholm, Sweden.
    Flock, B.
    Karolinska Institute, Stockholm, Sweden.
    Fridberger, Anders
    Karolinska Institute, Stockholm, Sweden.
    Jäger, W.
    Huddinge Hospital, Sweden.
    Methods for integrating fluorimetry in the study of hearing organ structure and function1997Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 106, nr 1-2, s. 29-38Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The measurement of function in the intact organ of Corti has up to now been achieved by three methods: electrophysiology, mechanical measurement and biochemical analysis. The two former methods have supplied information at the level of single identified cells. We have used a fourth method, optical fluorimetry, to measure hair cell function at the cellular level in the intact organ of Corti. Here we describe the methods involved in fluorescence labelling and video-enhanced microscopy in combination with electrophysiological recording of cochlear microphonic (CM) and summating potentials (SP). The guinea pig temporal bone containing an intact ear drum, ossicular chain and cochlea can be maintained in the isolated state by perfusion of the scala tympani with oxygenated tissue culture medium. Substances added to the perfusate readily diffuse through the basilar membrane into the organ of Corti. In this way cells in the organ can be stained by a number of fluorescent probes which label different structures and functions. Here we have used two dyes which label mitochondria and fluoresce with an intensity proportional to metabolic activity. By simultaneous measurement of CM and SP the functional state of the organ can be monitored.

  • 7.
    Fridberger, Anders
    et al.
    Karolinska Institutet, Stockholm, Sweden.
    Zheng, Jiefu
    Oregon Health Sciences University, Portland, USA.
    Nuttall, Alfred
    University of Michigan, Ann Arbor, USA.
    Alterations of basilar membrane response phase and velocity after acoustic overstimulation2002Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 167, nr 1-2, s. 214-222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To investigate the physiology of noise-induced hearing loss, the sound-induced vibrations of the basilar membrane (BM) of the inner ear were measured in living anesthetized guinea pigs before and after intense sound exposure. The vibrations were measured using a laser Doppler velocimeter after placing reflective glass beads on the BM. Pseudo-random noise waveforms containing frequencies between 4 and 24 kHz were used to generate velocity tuning curves. Before overstimulation, sharp response peaks were seen at stimulus frequencies between 15 and 17 kHz, consistent with the expected best frequency of the recording location. The response to low level stimuli lagged the high level ones by up to 90 degrees at the characteristic frequency. Following exposure to loud sound, the BM vibrations showed a pronounced reduction in amplitude, primarily at low stimulus levels, and the best frequency moved to approximately 12 kHz. At higher levels, the reduction was either absent or much smaller. In addition to the amplitude changes, increased phase lags were seen at frequencies near the characteristic frequency. In animals with more severe exposures, response phases were altered also at frequencies showing no change of the amplitude. The phase was independent of stimulus level after severe exposures.

  • 8.
    Koelewijn, Thomas
    et al.
    Vrije University of Amsterdam Medical Centre, Netherlands; Vrije University of Amsterdam Medical Centre, Netherlands.
    de Kluiver, Hilde
    Vrije University of Amsterdam Medical Centre, Netherlands; Vrije University of Amsterdam Medical Centre, Netherlands.
    Shinn-Cunningham, Barbara G.
    Boston University, MA 02215 USA.
    Zekveld, Adriana
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Institutet för handikappvetenskap (IHV). Vrije University of Amsterdam Medical Centre, Netherlands; Vrije University of Amsterdam Medical Centre, Netherlands.
    Kramer, Sophia E.
    Vrije University of Amsterdam Medical Centre, Netherlands; Vrije University of Amsterdam Medical Centre, Netherlands.
    The pupil response reveals increased listening effort when it is difficult to focus attention2015Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 323, s. 81-90Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies have shown that prior knowledge about where, when, and who is going to talk improves speech intelligibility. How related attentional processes affect cognitive processing load has not been investigated yet. In the current study, three experiments investigated how the pupil dilation response is affected by prior knowledge of target speech location, target speech onset, and who is going to talk. A total of 56 young adults with normal hearing participated. They had to reproduce a target sentence presented to one ear while ignoring a distracting sentence simultaneously presented to the other ear. The two sentences were independently masked by fluctuating noise. Target location (left or right ear), speech onset, and talker variability were manipulated in separate experiments by keeping these features either fixed during an entire block or randomized over trials. Pupil responses were recorded during listening and performance was scored after recall. The results showed an improvement in performance when the location of the target speech was fixed instead of randomized. Additionally, location uncertainty increased the pupil dilation response, which suggests that prior knowledge of location reduces cognitive load. Interestingly, the observed pupil responses for each condition were consistent with subjective reports of listening effort. We conclude that communicating in a dynamic environment like a cocktail party (where participants in competing conversations move unpredictably) requires substantial listening effort because of the demands placed on attentional processes. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

  • 9.
    Koelewijn, Thomas
    et al.
    Vrije University of Amsterdam, Netherlands Vrije University of Amsterdam, Netherlands .
    Shinn-Cunningham, Barbara G.
    Boston University, MA 02215 USA .
    Zekveld, Adriana
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten.
    Kramer, Sophia E.
    Vrije University of Amsterdam, Netherlands Vrije University of Amsterdam, Netherlands .
    The pupil response is sensitive to divided attention during speech processing2014Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 312, s. 114-120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dividing attention over two streams of speech strongly decreases performance compared to focusing on only one. How divided attention affects cognitive processing load as indexed with pupillometry during speech recognition has so far not been investigated. In 12 young adults the pupil response was recorded while they focused on either one or both of two sentences that were presented dichotically and masked by fluctuating noise across a range of signal-to-noise ratios. In line with previous studies, the performance decreases when processing two target sentences instead of one. Additionally, dividing attention to process two sentences caused larger pupil dilation and later peak pupil latency than processing only one. This suggests an effect of attention on cognitive processing load (pupil dilation) during speech processing in noise.

  • 10.
    Koelewijn, Thomas
    et al.
    Vrije Univ Amsterdam, Netherlands.
    Zekveld, Adriana A.
    Vrije Univ Amsterdam, Netherlands.
    Lunner, Thomas
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutet för handikappvetenskap (IHV). Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Logopedi, Audiologi och Otorhinolaryngologi. Eriksholm Res Ctr, Denmark; Tech Univ Denmark, Denmark.
    Kramer, Sophia E.
    Vrije Univ Amsterdam, Netherlands.
    The effect of reward on listening effort as reflected by the pupil dilation response2018Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 367, s. 106-112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Listening to speech in noise can be effortful but when motivated people seem to be more persevering. Previous research showed effects of monetary reward on autonomic responses like cardiovascular reactivity and pupil dilation while participants processed auditory information. The current study examined the effects of monetary reward on the processing of speech in noise and related listening effort as reflected by the pupil dilation response. Twenty-four participants (median age 21 yrs) performed two speech reception threshold (SRT) tasks, one tracking 50% correct (hard) and one tracking 85% correct (easy), both of which they listened to and repeated sentences uttered by a female talker. The sentences were presented with a single male talker or, in a control condition, in quiet. Participants were told that they could earn a high (5 euros) or low (0.20 euro) reward when repeating 70% or more of the sentences correctly. Conditions were presented in a blocked fashion and during each trial, pupil diameter was recorded. At the end of each block, participants rated the effort they had experienced, their performance, and their tendency to quit listening. Additionally, participants performed a working memory capacity task and filled in a need-for-recovery questionnaire as these tap into factors that influence the pupil dilation response. The results showed no effect of reward on speech perception performance as reflected by the SRT. The peak pupil dilation showed a significantly larger response for high than for low reward, for the easy and hard conditions, but not the control condition. Higher need for recovery was associated with a higher subjective tendency to quit listening. Consistent with the Framework for Understanding Effortful Listening, we conclude that listening effort as reflected by the peak pupil dilation is sensitive to the amount of monetary reward. (C) 2018 The Authors. Published by Elsevier B.V.

  • 11.
    Kytovuori, Laura
    et al.
    Oulu University Hospital, Finland; University of Oulu, Finland; University of Oulu, Finland; Oulu University Hospital, Finland.
    Hannula, Samuli
    Oulu University Hospital, Finland; University of Oulu, Finland; Oulu University Hospital, Finland; University of Oulu, Finland.
    Mäki-Torkko, Elina
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Logopedi, Audiologi och Otorhinolaryngologi. Linköpings universitet, Medicinska fakulteten. Oulu University Hospital, Finland.
    Sorri, Martti
    Oulu University Hospital, Finland; University of Oulu, Finland; Oulu University Hospital, Finland; University of Oulu, Finland.
    Majamaa, Kari
    Oulu University Hospital, Finland; University of Oulu, Finland; University of Oulu, Finland; Oulu University Hospital, Finland.
    A nonsynonymous mutation in the WFS1 gene in a Finnish family with age-related hearing impairment2017Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 355, s. 97-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wolfram syndrome (WS) is caused by recessive mutations in the Wolfram syndrome 1 (WFS1) gene. Sensorineural hearing impairment (HI) is a frequent feature in WS and, furthermore, certain mutations in WFS1 cause nonsyndromic dominantly inherited low-frequency sensorineural HI. These two phenotypes are clinically distinct indicating that WFS1 is a reasonable candidate for genetic studies in patients with other phenotypes of HI. Here we have investigated, whether the variation in WFS1 has a pathogenic role in age-related hearing impairment (ARHI). WFS1 gene was investigated in a population sample of 518 Finnish adults born in 1938-1949 and representing variable hearing phenotypes. Identified variants were evaluated with respect to pathogenic potential. A rare mutation predicted to be pathogenic was found in a family with many members with impaired hearing. Twenty members were recruited to a segregation study and a detailed clinical examination. Heterozygous p.Tyr528His variant segregated completely with late-onset HI in which hearing deteriorated first at high frequencies and progressed to mid and low frequencies later in life. We report the first mutation in the WFS1 gene causing late-onset HI with audiogram configurations typical for ARHI. Monogenic forms of ARHI are rare and our results add WFS1 to the short list of such genes. (C) 2017 Elsevier B.V. All rights reserved.

  • 12. Nuttall, Alfred L
    et al.
    Fridberger, Anders
    Karolinska Institutet, Stockholm, Sweden.
    Instrumentation for studies of cochlear mechanics: from von Békésy forward2012Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 293, nr 1-2, s. 3-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Georg von Békésy designed the instruments needed for his research. He also created physical models of the cochlea allowing him to manipulate the parameters (such as volume elasticity) that could be involved in controlling traveling waves. This review is about the specific devices that he used to study the motion of the basilar membrane thus allowing the analysis that lead to his Nobel Prize Award. The review moves forward in time mentioning the subsequent use of von Békésy's methods and later technologies important for motion studies of the organ of Corti. Some of the seminal findings and the controversies of cochlear mechanics are mentioned in relation to the technical developments.

  • 13.
    Ohlenforst, Barbara
    et al.
    Vrije Univ Amsterdam, Netherlands; Amsterdam Publ Hlth Res Inst, Netherlands; Oticon AS, Denmark.
    Wendt, Dorothea
    Oticon AS, Denmark; Tech Univ Denmark, Denmark.
    Kramer, Sophia E.
    Vrije Univ Amsterdam, Netherlands; Amsterdam Publ Hlth Res Inst, Netherlands.
    Naylor, Graham
    MRC CSO Inst Hearing Res, Scotland; Univ Nottingham, England.
    Zekveld, Adriana
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutet för handikappvetenskap (IHV). Vrije Univ Amsterdam, Netherlands; Amsterdam Publ Hlth Res Inst, Netherlands; Orebro Univ, Sweden.
    Lunner, Thomas
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutet för handikappvetenskap (IHV). Orebro Univ, Sweden; Oticon AS, Denmark; Tech Univ Denmark, Denmark.
    Impact of SNR, masker type and noise reduction processing on sentence recognition performance and listening effort as indicated by the pupil dilation response2018Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 365, s. 90-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies have shown that activating the noise reduction scheme in hearing aids results in a smaller peak pupil dilation (PPD), indicating reduced listening effort, at 50% and 95% correct sentence recognition with a 4-talker masker. The objective of this study was to measure the effect of the noise reduction scheme (on or off) on PPD and sentence recognition across a wide range of signal-to-noise ratios (SNRs) from +16 dB to -12 dB and two masker types (4-talker and stationary noise). Relatively low PPDs were observed at very low (-12 dB) and very high (+16 dB to +8 dB) SNRs presumably due to giving up and easy listening, respectively. The maximum PPD was observed with SNRs at approximately 50% correct sentence recognition. Sentence recognition with both masker types was significantly improved by the noise reduction scheme, which corresponds to the shift in performance from SNR function at approximately 5 dB toward a lower SNR. This intelligibility effect was accompanied by a corresponding effect on the PPD, shifting the peak by approximately 4 dB toward a lower SNR. In addition, with the 4-talker masker, when the noise reduction scheme was active, the PPD was smaller overall than that when the scheme was inactive. We conclude that with the 4-talker masker, noise reduction scheme processing provides a listening effort benefit in addition to any effect associated with improved intelligibility. Thus, the effect of the noise reduction scheme on listening effort incorporates more than can be explained by intelligibility alone, emphasizing the potential importance of measuring listening effort in addition to traditional speech reception measures. (C) 2018 Elsevier B.V. All rights reserved.

  • 14.
    Ohlenforst, Barbara
    et al.
    Vrije University of Amsterdam, Netherlands; Amsterdam Public Health Research Institute, Netherlands; Oticon AS, Denmark.
    Zekveld, Adriana
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Institutet för handikappvetenskap (IHV). Linköpings universitet, Filosofiska fakulteten. Vrije University of Amsterdam, Netherlands; Amsterdam Public Health Research Institute, Netherlands.
    Lunner, Thomas
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutet för handikappvetenskap (IHV). Oticon AS, Denmark.
    Wendt, Dorothea
    Oticon AS, Denmark; Technical University of Denmark, Denmark.
    Naylor, Graham
    MRC CSO Institute Hearing Research, Scotland.
    Wang, Yang
    Vrije University of Amsterdam, Netherlands; Amsterdam Public Health Research Institute, Netherlands; Oticon AS, Denmark.
    Versfeld, Niek J.
    Vrije University of Amsterdam, Netherlands; Amsterdam Public Health Research Institute, Netherlands.
    Kramer, Sophia E.
    Vrije University of Amsterdam, Netherlands; Amsterdam Public Health Research Institute, Netherlands.
    Impact of stimulus-related factors and hearing impairment on listening effort as indicated by pupil dilation2017Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 351, s. 68-79Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous research has reported effects of masker type and signal-to-noise ratio (SNR) on listening effort, as indicated by the peak pupil dilation (PPD) relative to baseline during speech recognition. At about 50% correct sentence recognition performance, increasing SNRs generally results in declining PPDs, indicating reduced effort. However, the decline in PPD over SNRs has been observed to be less pronounced for hearing-impaired (HI) compared to normal-hearing (NH) listeners. The presence of a competing talker during speech recognition generally resulted in larger PPDs as compared to the presence of a fluctuating or stationary background noise. The aim of the present study was to examine the interplay between hearing-status, a broad range of SNRs corresponding to sentence recognition performance varying from 0 to 100% correct, and different masker types (stationary noise and single-talker masker) on the PPD during speech perception. Twenty-five HI and 32 age-matched NH participants listened to sentences across a broad range of SNRs, masked with speech from a single talker (-25 dB to +15 dB SNR) or with stationary noise (-12 dB to +16 dB). Correct sentence recognition scores and pupil responses were recorded during stimulus presentation. With a stationary masker, NH listeners show maximum PPD across a relatively narrow range of low SNRs, while HI listeners show relatively large PPD across a wide range of ecological SNRs. With the single-talker masker, maximum PPD was observed in the mid-range of SNRs around 50% correct sentence recognition performance, while smaller PPDs were observed at lower and higher SNRs. Mixed-model ANOVAs revealed significant interactions between hearing-status and SNR on the PPD for both masker types. Our data show a different pattern of PPDs across SNRs between groups, which indicates that listening and the allocation of effort during listening in daily life environments may be different for NH and HI listeners. (C) 2017 The Authors. Published by Elsevier B.V.

  • 15.
    Palmgren, Björn
    et al.
    Karolinska University Hospital, Stockholm, Sweden.
    Jin, Zhe
    Uppsala University, Sweden .
    Ma, Hongmin
    Karolinska University Hospital, Stockholm, Sweden.
    Jiao, Yu
    Karolinska University Hospital, Stockholm, Sweden.
    Olivius, Petri
    Karolinska University Hospital, Stockholm, Sweden.
    β-Bungarotoxin application to the round window: An in vivo deafferentation model of the inner ear2010Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 265, nr 1-2, s. 70-76Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hearing impairment can be caused by a primary lesion to the spiral ganglion neurons (SGNs) with the hair cells kept intact, for example via tumours, trauma or auditory neuropathy. To mimic these conditions in animal models various methods of inflicting damage to the inner ear have been used. However, only a few methods have a selective effect on the SGNs, which is of importance since it might be clinically more relevant to study hearing impairment with the hair cells undamaged. beta-Bungarotoxin is a venom of the Taiwan banded krait, which in vitro has been shown to induce apoptosis in neurons, leaving remaining cochlear cells intact. We wanted to create an in vivo rat model of selective damage to primary auditory neurons. Under deep anaesthesia, 41 rats received beta-Bungarotoxin or saline to the round window niche. At postoperative intervals between days 3 and 21 auditory brainstem response (ABR) measurement, immunohistochemistry, SGN quantification and cochlear surface preparation were performed. The results in the beta-Bungarotoxin-treated ears, as compared with sham-operated ears, show significantly increased ABR thresholds at all postoperative intervals, illustrating a severe to profound hearing loss at all tested frequencies (3.5, 7, 16 and 28 kHz). Quantification of the SGNs showed no obvious reduction in neuronal numbers until 14 days postoperatively. Between days 14 and 21 a significant reduction in SGN numbers was observed. Cochlear surface preparation and immunohistochemistry showed that the hair cells were intact. Our results illustrate that in vivo application of beta-Bungarotoxin to the round window niche is a feasible way of deafening rats by SGN reduction while the hair cells are kept intact.

  • 16.
    Reinfeldt, Sabine
    et al.
    Chalmers University of Technology, Göteborg, Sweden.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Håkansson, Bo
    Chalmers University of Technology, Göteborg, Sweden.
    Estimation of bone conduction skull transmission by hearing thresholds and ear-canal sound pressure2013Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 299, s. 19-28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bone conduction sound transmission in the human skull and the occlusion effect were estimated from hearing thresholds and ear-canal sound pressure (ECSP) measured by a probe tube microphone when stimulation was at three positions on the skull (ipsilateral mastoid, contralateral mastoid, and forehead). The measurements were done with the ear-canal open as well as occluded by an ear-plug. Depending on the estimation method, transcranial transmission at frequencies below 1 kHz was between −8 and 5 dB, around 0 dB at 1 kHz that decreased with frequency to between −17 and −7 dB at 8 kHz. The forehead transmission was, except at frequencies between 1 and 2 kHz, similar to that proposed in the standard ISO:389-3 (1994) when the threshold measurements were conducted with open ear-canals. Compared with the same measurements using hearing thresholds, the ECSP gave similar transmission results at most frequencies, but differed at 0.5, 0.75, 2 and 3 kHz. One probable reason for the differences between thresholds and ECSP might be a significant perception improvement (lower thresholds) when the stimulation was at the ipsilateral mastoid that was not found at the other positions. This improvement, which also was present in the occlusion effect data, was hypothesized to originate in greater sensitivity of the cochlea for vibration in line with the ipsilateral stimulation direction than from other directions.

  • 17.
    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
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    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 head2016Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 340, s. 153-160Artikel i tidskrift (Refereegranskat)
    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.

  • 18.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Inner ear contribution to bone conduction hearing in the human2015Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 329, s. 41-51Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 19.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Model predictions for bone conduction perception in the human2016Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, nr 15, s. 30076-30079Artikel i tidskrift (Refereegranskat)
    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.

  • 20.
    Stenfelt, Stefan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för nervsystem och rörelseorgan, Teknisk audiologi.
    Simultaneous cancellation of air and bone conduction tones at two frequencies: Extension of the famous experiment by von Békésy2007Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 225, nr 1-2, s. 105-116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cancellation experiments between air conduction (AC) and bone conduction (BC) tones were conducted at two frequencies (0.7 and 1.1 kHz) and three levels (40, 50, and 60 dB HL) in three subjects. The tests were divided into three categories: (1) single tone cancellation, (2) simultaneous cancellation of two tones, and (3) cancellation of one tone while a disturbing tone was present. In total, each subject performed twelve cancellation tasks. The hypothesis is that the AC and BC sound transmission behaves as linear systems and they both excite the basilar membrane in the cochlea similarly. The cancellation results are presented as the deviations from this hypothesis, except for a few larger deviations, the intrasubject deviations were generally less than 0.5 dB and 5°. The results from all three test categories indicate that the hypothesis of linear transmission systems and similarity of cochlear stimulation by AC and BC holds. However, due to the subjects' limited ability to conduct optimal cancellation and to imperfect methodology and equipment, the small deviations from perfectly linear cancellation that were observed do neither conclusively prove nor refute the possibility of small differences in the cochlear processing of AC and BC sound. Nonetheless, it is clear that if such differences in the processing of the two stimuli exist, they are small in magnitude. © 2006 Elsevier B.V. All rights reserved.

  • 21.
    Stenfelt, Stefan
    et al.
    Chalmers University of Technology.
    Hato, N
    Stanford.
    Goode, RL
    Stanford.
    Round window membrane motion with air conduction and bone conduction stimulation2004Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 198, nr 02-Jan, s. 10-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The vibration patterns of the round window (RW) membrane in human cadaver temporal bone specimens were assessed by measurements of the velocity of reflective targets placed on the RW membrane with an approximate spacing of 0.2 mm. The velocity was measured in the frequency range 0.1-10 kHz by a laser Doppler vibrometer in four specimens with air conduction (AC) stimulation and in four specimens with bone conduction (BC) stimulation. The response pattern was investigated by analyzing the velocity response of all targets on the RW membrane, by making iso-amplitude and iso-phase contour plots of the membrane surface, and by creating animations of the surface vibration at several frequencies. Similar response pattern was found with AC and BC stimulations. At frequencies below 1.5 kHz, the RW membrane vibrates nearly as a whole in an in-and-out motion and above 1.5 kHz, the membrane moves primarily in two sections that vibrate with approximately 180degrees difference. Indication of some traveling wave motion of the RW membrane at those frequencies was also found. At higher frequencies, above 3 kHz, the membrane motion is complex with a mixture of modal and traveling wave motion. An increase of the stimulation level did not alter the vibration pattern; it only gave an increase of the RW membrane vibration amplitude corresponding to the increase in stimulation. When the mode of stimulation at the oval window was altered, by the insertion of a 0.6 mm piston, the vibration pattern of the RW membrane changed.

  • 22.
    Stenfelt, Stefan
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Håkansson, Bo
    Chalmers.
    Air versus bone conduction: An equal loudness investigation2002Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 167, nr 1-2, s. 1-12Artikel i tidskrift (Refereegranskat)
  • 23.
    Stenfelt, Stefan
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Puria, Sunil
    Stanford University.
    Hato, Naohito
    Stanford University.
    Goode, Richard
    Stanford university.
    Basilar membrane and osseous spiral lamina motion in human cadavers with air and bone conduction stimuli2004Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 198, nr 1-2, s. 10-24Artikel i tidskrift (Refereegranskat)
  • 24.
    Stenfelt, Stefan
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Zeitooni, Mehrnaz
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Teknisk audiologi. Linköpings universitet, Hälsouniversitetet.
    Loudness functions with air and bone conduction stimulation in normal-hearing subjects using a categorical loudness scaling procedure2013Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 301, s. 85-92Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In a previous study (Stenfelt and Håkansson, 2002) a loudness balance test between bone conducted (BC) sound and air conducted (AC) sound was performed at frequencies between 0.25 and 4 kHz and at levels corresponding to 30–80 dB HL. The main outcome of that study was that for maintaining equal loudness, the level increase of sound with BC stimulation was less than that of AC stimulation with a ratio between 0.8 and 0.93 dB/dB. However, because it was shown that AC and BC tone cancellation was independent of the stimulation level, the loudness level difference did not originate in differences in basilar membrane stimulation. Therefore, it was speculated that the result could be due to the loudness estimation procedure. To investigate this further, another loudness estimation method (adaptive categorical loudness scaling) was here employed in 20 normal-hearing subjects.

    The loudness of a low-frequency and a high-frequency noise burst was estimated using the adaptive categorical loudness scaling technique when the stimulation was bilaterally by AC or BC. The sounds where rated on an 11-point scale between inaudible and too loud. The total dynamic range for these sounds was over 80 dB when presented by AC (between inaudible and too loud) and the loudness functions were similar for the low and the high-frequency stimulation. When the stimulation was by BC the loudness functions were steeper and the ratios between the slopes of the AC and BC loudness functions were 0.88 for the low-frequency sound and 0.92 for the high-frequency sound. These results were almost equal to the previous published results using the equal loudness estimation procedure, and it was unlikely that the outcome stems from the loudness estimation procedure itself. One possible mechanism for the result was loudness integration of multi-sensory input. However, no conclusive evidence for such a mechanism could be given by the present study.

  • 25.
    Strömberg, Anna-Karin
    et al.
    Region Östergötland, Sinnescentrum, Öron- näsa- och halskliniken US. Karolinska Hospital, Sweden.
    Olofsson, Åke
    Karolinska Institute, Sweden.
    Westin, Magnus
    Karolinska Hospital, Sweden.
    Duan, Maoli
    Karolinska Hospital, Sweden; Karolinska Institute Stockholm, Sweden.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Changes in cochlear function related to acoustic stimulation of cervical vestibular evoked myogenic potential stimulation2016Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 340, s. 43-49Artikel i tidskrift (Refereegranskat)
    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.

  • 26.
    Wendt, Dorothea
    et al.
    Eriksholm Res Ctr, Denmark; Tech Univ Denmark, Denmark.
    Koelewijn, Thomas
    Vrije Univ Amsterdam Med Ctr, Netherlands.
    Ksiazek, Patrycja
    Eriksholm Res Ctr, Denmark.
    Kramer, Sophia E.
    Vrije Univ Amsterdam Med Ctr, Netherlands.
    Lunner, Thomas
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutet för handikappvetenskap (IHV). Eriksholm Res Ctr, Denmark; Tech Univ Denmark, Denmark.
    Toward a more comprehensive understanding of the impact of masker type and signal-to-noise ratio on the pupillary response while performing a speech-in-noise test2018Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 369, s. 67-78Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Difficulties arising in everyday speech communication often result from the acoustical environment, which may contain interfering background noise or competing speakers. Thus, listening and understanding speech in noise can be exhausting. Two experiments are presented in the current study that further explored the impact of masker type and Signal-to-Noise Ratio (SNR) on listening effort by means of pupillometry. In both studies, pupillary responses of participants were measured while performing the Danish Hearing in Noise Test (HINT; Nielsen and Dau, 2011). The first experiment aimed to replicate and extend earlier observed effects of noise type and semantic interference on listening effort (Koelewijn et al., 2012). The impact of three different masker types, i.e. a fluctuating noise, a 1-talker masker and a 4-talker masker on listening effort was examined at a fixed speech intelligibility. In a second experiment, effects of SNR on listening effort were examined while presenting the HINT sentences across a broad range of fixed SNRs corresponding to intelligibility scores ranging from 100% to 0% correct performance. A peak pupil dilation (PPD) was calculated and a Growth Curve Analysis (GCA) was performed to examine listening effort involved in speech recognition as a function of SNR. The results of two experiments showed that the pupil dilation response is highly affected by both masker type and SNR when performing the HINT. The PPD was highest, suggesting the highest level of effort, for speech recognition in the presence of the 1-talker masker in comparison to the 4-talker babble and the fluctuating noise masker. However, the disrupting effect of one competing talker disappeared for intelligibly levels around 50%. Furthermore, it was demonstrated that the pupillary response strongly varied as a function of SNRs. Listening effort was highest for intermediate SNRs with performance accuracies ranging between 30% and 70% correct. GCA revealed time-dependent effects of the SNR on the pupillary response that were not reflected in the PPD. (C) 2018 Elsevier B.V. All rights reserved.

  • 27.
    Zhao, Mingduo
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Logopedi, Audiologi och Otorhinolaryngologi. Linköpings universitet, Medicinska fakulteten.
    Fridberger, Anders
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Stenfelt, Stefan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för Logopedi, Audiologi och Otorhinolaryngologi. Linköpings universitet, Medicinska fakulteten.
    Bone conduction hearing in the Guinea pig and the effect of artificially induced middle ear lesions2019Ingår i: Hearing Research, ISSN 0378-5955, E-ISSN 1878-5891, Vol. 379, s. 21-30Artikel i tidskrift (Refereegranskat)
    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.

    Publikationen är tillgänglig i fulltext från 2020-04-17 07:26
1 - 27 av 27
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf