This study aimed to: (1) examine the influence of working memory capacity on the ability of experienced hearing aid users to recognize speech in noise using new noise reduction settings, and (2) investigate whether male and female hearing aid users differ in their hearing sensitivity and ability to recognize aided speech in noisy environments. 195 experienced hearing aid users (113 males and 82 females, age range: 33?80 years) from the n200 project were investigated. The Hagerman test (capturing speech recognition in noise) was administered using an experimental hearing aid with two digital signal processing settings: (1) linear amplification without noise reduction (NoP), and (2) linear amplification with noise reduction (NR). Gender differences were analysed using a series of independent samples from t-tests on Hagerman sentence scores, and the pure-tone average thresholds across the frequencies 500, 1000, 2000, and 4000?Hz (PTA4) for the left ear and right ear were measured. Working memory capacity (WMC) was measured using a reading span test. A WMC grouping (high and low) was included as a between-group subject factor in the within-group factors ANOVA, NR settings (Nop, NR), noise type (steady state noise, four -talker babble), and level of performance (50%, 80%). Male listeners had better pure-tone thresholds than female listeners at frequencies 500 and 1000?Hz, whereas female listeners had better pure-tone thresholds at 4000?Hz. Female listeners showed significantly better speech recognition ability than male listeners on the Hagerman test with NR , but not with NoP . This gender difference was more pronounced at the 80% performance level than at the 50% level. WMC had a significant effect on speech recognition ability, and there was a two-way interaction between WMC grouping and level of performance. The examination of simple main effects revealed superior performance of listeners with higher WMC at 80% using new NR settings. WMC, rather than background noise, was the main factor influencing performance at 80%, while at 50%, background noise was the main factor. WMC was associated with speech recognition performance even after accounting for hearing sensitivity (PTA4). This is the first study to demonstrate that experienced male and female hearing aid users differ significantly in their hearing ability and sensitivity and ability to recognize aided speech in noise. Thus, the average female listener has a greater speech recognition ability than the average male listener when linear amplification with NR is applied, but not when NoP is activated. An average female listener hears a given sound with greater sensitivity compared with an average male listener at higher frequencies. WMC is an important factor in speech recognition in more challenging listening conditions (i.e., lower signal?noise ratio) for experienced hearing aid users using new NR settings. More investigation is needed for a better understanding of how gender affects the ability of listeners less experienced with hearing aids (such as younger and elderly hearing-impaired listeners) to recognize speech amplified with different signal processing, as gender differences may vary based on numerous factors, including the speaker?s gender and age.

Objective: Previous work examining speech recognition in more challenging listening environments has revealed a large variability in both persons with normal and hearing impairments. Although this is clinically very important, up to now, no consensus has been reached about which factors may provide better explanation for the existing individual variability in speech recognition ability among hearing aid users, when speech signal is degraded. This study aimed to examine hearing-sensitivity skills and cognitive ability differences between listeners with good and poor speech recognition abilities. 

Materials and Methods: A total of 195 experienced hearing aid users (33–80 years) were grouped by higher or lower speech recognition ability based on their performance on the Hagerman sentences task in multi-talker babble using fast-acting compression algorithm. They completed a battery of cognitive abilities tests, hearing-in-noise and the auditory thresholds test. 

Results: The results showed that the two groups did differ significantly overall on cognitive abilities tests like working memory, cognitive processing speed and attentional shifting, but not on the attentional inhibitory test and non-verbal intelligence test. 

Conclusions: Listeners with poor compared to those with better speech recognition abilities exhibit poorer cognitive abilities, which place them in a disadvantaged position, and /or more susceptible to signal modifications (as a result of fast-acting compression signal processing), resulting in limited benefits from hearing aids strategies. The findings may have implications for hearing aid signal processing strategies selection in rehabilitations.

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.

Previous studies have demonstrated that speech recognition in noise is associated with hearing aid compression release settings and cognitive processing speed. This study investigated the effects of Cognitive processing speed and Digital Signal Processing settings (linear amplification without noise reduction, linear amplification with noise reduction and non-linear amplification with (fast-acting compression without noise reduction) on the performance of speech recognition task in noise in elderly hearing aid users. Two hundred elderly (mean age = 61 years) experienced hearing aid users with sensorineural hearing loss participated in the study. Individual measurements of Cognitive processing speed (rapid automatic naming test), Speech recognition in noise (Hagerman test) were obtained and used to predict a successful outcome. The results will be presented and the potential clinical implications in the rehabilitations of elderly hearing aid users discussed.