Search

Purpose: A relevant aspect of listening is the effort required during speech processing, which can be assessed by pupillometry. Here, we assessed the pupil dilation response of normal-hearing (NH) and hard of hearing (HH) individuals during listening to clear sentences and masked or degraded sentences. We combined this assessment with functional magnetic resonance imaging (fMRI) to investigate the neural correlates of the pupil dilation response., Method: Seventeen NH participants ( M age = 46 years) were compared to 17 HH participants ( M age = 45 years) who were individually matched in age and educational level. Participants repeated sentences that were presented clearly, that were distorted, or that were masked. The sentence intelligibility level of masked and distorted sentences was 50% correct. Silent baseline trials were presented as well. Performance measures, pupil dilation responses, and fMRI data were acquired., Results: HH individuals had overall poorer speech reception than the NH participants, but not for noise-vocoded speech. In addition, an interaction effect was observed with smaller pupil dilation responses in HH than in NH listeners for the degraded speech conditions. Hearing impairment was associated with higher activation across conditions in the left superior temporal gyrus, as compared to the silent baseline. However, the region of interest analysis indicated lower activation during degraded speech relative to clear speech in bilateral frontal regions and the insular cortex, for HH compared to NH listeners. Hearing impairment was also associated with a weaker relation between the pupil response and activation in the right inferior frontal gyrus. Overall, degraded speech evoked higher frontal activation than clear speech., Conclusion: Brain areas associated with attentional and cognitive-control processes may be increasingly recruited when speech is degraded and are related to the pupil dilation response, but this relationship is weaker in HH listeners., Supplemental Material: https://doi.org/10.23641/asha.27162135.

Previous research has shown that learning effects are present for speech intelligibility in temporally modulated (TM) noise, but not in stationary noise. The present study aimed to gain more insight into the factors that might affect the time course (the number of trials required to reach stable performance) and size [the improvement in the speech reception threshold (SRT)] of the learning effect. Two hypotheses were addressed: (1) learning effects are present in both TM and spectrally modulated (SM) noise and (2) the time course and size of the learning effect depend on the amount of masking release caused by either TM or SM noise. Eighteen normal-hearing adults (23-62 years) participated in SRT measurements, in which they listened to sentences in six masker conditions, including stationary, TM, and SM noise conditions. The results showed learning effects in all TM and SM noise conditions, but not for the stationary noise condition. The learning effect was related to the size of masking release: a larger masking release was accompanied by an increased time course of the learning effect and a larger learning effect. The results also indicate that speech is processed differently in SM noise than in TM noise., (© 2024 Acoustical Society of America.)

In recent studies, psychophysiological measures have been used as markers of listening effort, but there is limited research on the effect of hearing loss on such measures. The aim of the current study was to investigate the effect of hearing acuity on physiological responses and subjective measures acquired during different levels of listening demand, and to investigate the relationship between these measures. A total of 125 participants (37 males and 88 females, age range 37-72 years, pure-tone average hearing thresholds at the best ear between -5.0 to 68.8 dB HL and asymmetry between ears between 0.0 and 87.5 dB) completed a listening task. A speech reception threshold (SRT) test was used with target sentences spoken by a female voice masked by male speech. Listening demand was manipulated using three levels of intelligibility: 20 % correct speech recognition, 50 %, and 80 % (IL20 %/IL50 %/IL80 %, respectively). During the task, peak pupil dilation (PPD), heart rate (HR), pre-ejection period (PEP), respiratory sinus arrhythmia (RSA), and skin conductance level (SCL) were measured. For each condition, subjective ratings of effort, performance, difficulty, and tendency to give up were also collected. Linear mixed effects models tested the effect of intelligibility level, hearing acuity, hearing asymmetry, and tinnitus complaints on the physiological reactivity (compared to baseline) and subjective measures. PPD and PEP reactivity showed a non-monotonic relationship with intelligibility level, but no such effects were found for HR, RSA, or SCL reactivity. Participants with worse hearing acuity had lower PPD at all intelligibility levels and showed lower PEP baseline levels. Additionally, PPD and SCL reactivity were lower for participants who reported suffering from tinnitus complaints. For IL80 %, but not IL50 % or IL20 %, participants with worse hearing acuity rated their listening effort to be relatively high compared to participants with better hearing. The reactivity of the different physiological measures were not or only weakly correlated with each other. Together, the results suggest that hearing acuity may be associated with altered sympathetic nervous system (re)activity. Research using psychophysiological measures as markers of listening effort to study the effect of hearing acuity on such measures are best served by the use of the PPD and PEP., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

In daily life, both acoustic factors and social context can affect listening effort investment. In laboratory settings, information about listening effort has been deduced from pupil and cardiovascular responses independently. The extent to which these measures can jointly predict listening-related factors is unknown. Here we combined pupil and cardiovascular features to predict acoustic and contextual aspects of speech perception. Data were collected from 29 adults (mean  =  64.6 years, SD  =  9.2) with hearing loss. Participants performed a speech perception task at two individualized signal-to-noise ratios (corresponding to 50% and 80% of sentences correct) and in two social contexts (the presence and absence of two observers). Seven features were extracted per trial: baseline pupil size, peak pupil dilation, mean pupil dilation, interbeat interval, blood volume pulse amplitude, pre-ejection period and pulse arrival time. These features were used to train k-nearest neighbor classifiers to predict task demand, social context and sentence accuracy. The k-fold cross validation on the group-level data revealed above-chance classification accuracies: task demand, 64.4%; social context, 78.3%; and sentence accuracy, 55.1%. However, classification accuracies diminished when the classifiers were trained and tested on data from different participants. Individually trained classifiers (one per participant) performed better than group-level classifiers: 71.7% (SD  =  10.2) for task demand, 88.0% (SD  =  7.5) for social context, and 60.0% (SD  =  13.1) for sentence accuracy. We demonstrated that classifiers trained on group-level physiological data to predict aspects of speech perception generalized poorly to novel participants. Individually calibrated classifiers hold more promise for future applications., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: Current evidence regarding the influence of hearing loss on the pupil response elicited by speech perception is inconsistent. This might be partially due to confounding effects of age. This study aimed to compare pupil responses in age-matched groups of normal-hearing (NH) and hard of hearing (HH) listeners during listening to speech., Method: We tested the baseline pupil size and mean and peak pupil dilation response of 17 NH participants ( M age = 46 years; age range: 20-62 years) and 17 HH participants ( M age = 45 years; age range: 20-63 years) who were pairwise matched on age and educational level. Participants performed three speech perception tasks at a 50% intelligibility level: noise-vocoded speech and speech masked with either stationary noise or interfering speech. They also listened to speech presented in quiet., Results: Hearing loss was associated with poorer speech perception, except for noise-vocoded speech. In contrast to NH participants, performance of HH participants did not improve across trials for the interfering speech condition, and it decreased for speech in stationary noise. HH participants had a smaller mean pupil dilation in degraded speech conditions compared to NH participants, but not for speech in quiet. They also had a steeper decline in the baseline pupil size across trials. The baseline pupil size was smaller for noise-vocoded speech as compared to the other conditions. The normalized data showed an additional group effect on the baseline pupil response., Conclusions: Hearing loss is associated with a smaller pupil response and steeper decline in baseline pupil size during the perception of degraded speech. This suggests difficulties of the HH participants to sustain their effort investment and performance across the test session.

Objectives: To assess if a manipulation of copresence was related to speech-in-noise task performance, arousal, and effort of persons with hearing loss. Task-related arousal and effort were measured by means of pupillometry., Design: Twenty-nine participants (mean age: 64.6 years) with hearing loss (4-frequency pure-tone average [4F-PTA] of 50.2 dB HL [SD = 8.9 dB] in the right ear and 51.3 dB HL [SD = 8.7 dB] in the left ear; averaged across 0.5, 1, 2, and 4 kHz) listened to and repeated spoken Danish sentences that were masked by four streams of continuous speech. Participants were presented with blocks of 20 sentences, during which copresence was manipulated by having participants do the task either alone or accompanied by two observers who were recruited from a similar age group. The task was presented at two difficulty levels, which was accomplished by fixing the signal-to-noise ratio of the speech and masker to match the thresholds at which participants were estimated to correctly repeat 50% (difficult) or 80% (easy) of the sentences in a block. Performance was assessed based on whether or not sentences were repeated correctly. Measures of pupil size (baseline pupil size [BPS], peak pupil dilation [PPD], and mean pupil dilation [MPD]) were used to index arousal and effort. Participants also completed ratings of subjective effort and stress after each block of sentences and a self-efficacy for listening-questionnaire., Results: Task performance was not associated with copresence, but was found to be related to 4F-PTA. An increase in BPS was found for copresence conditions, compared to alone conditions. Furthermore, a post-hoc exploratory analysis revealed that the copresence conditions were associated with a significantly larger pupil size in the second half of the task-evoked pupil response (TEPR). No change in PPD or MPD did was detected between copresence and alone conditions. Self-efficacy, 4F-PTA, and age were not found to be related to the pupil data. Subjective ratings were sensitive to task difficulty but not copresence., Conclusion: Copresence was not found to be related to speech-in-noise performance, PPD, or MPD in persons with HL but was associated with an increase in arousal (as indicated by a larger BPS). This could be related to premobilization of effort and/or discomfort in response to the observers' presence. Furthermore, an exploratory analysis of the pupil data showed that copresence was associated with greater pupil dilations in the second half of the TEPR. This may indicate that participants invested more effort during the speech-in-noise task while in the presence of the observers, but that this increase in effort may not necessarily have been related to listening itself. Instead, other speech-in-noise task-related processes, such as preparing to respond, could have been influenced by copresence., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2023 The Authors. Ear & Hearing is published on behalf of the American Auditory Society, by Wolters Kluwer Health, Inc.)

Objectives: The first aim of this study was to examine the relationship between having tinnitus and the need for recovery after work (NFR). The second aim was to investigate whether the level of tinnitus annoyance is associated with NFR., Design: Data from the 5- and 10-year follow-up measurement rounds of the Netherlands Longitudinal Study on Hearing (NL-SH) were used in a cross-sectional analyses. The NL-SH is a web-based prospective cohort study and includes participants aged 18 to 70 years at baseline. For this study, we included only participants who worked at least 12 hours/week and were under the age of 65 years. Participants completed questionnaires on demographic, socioeconomic, psychosocial, hearing-related, and work-related characteristics. In addition, participants answered questions about hearing ability and tinnitus and performed an online digit-triplet speech recognition in noise test to measure the speech reception threshold (SRT) in noise. Participants were asked if (1) they suffer from tinnitus and (2) to rate tinnitus annoyance on a 0-100 numeric rating scale. A linear mixed model was used (1) to estimate the overall (i.e., cross-sectional) association between having tinnitus and NFR and (2) to estimate the overall association between the level of tinnitus annoyance and NFR. The models were checked for effect modification and confounding of factors known to be associated with either tinnitus or NFR and available in the NL-SH., Results: The study sample comprised 770 unique participants in total; 686 and 335 participants at 5- and 10-year follow-up, respectively. Distress, somatization, and self-reported hearing disability appeared to be confounding factors in the analysis of having tinnitus and NFR. After adjusting for these factors, participants with tinnitus had a 2.5% higher NFR (95% confidence interval: -0.9 to 5.9; p = 0.15). In the analysis of tinnitus annoyance and NFR, SRT was an effect modifier. Distress, somatization, depression, and self-reported hearing disability were confounders. After adjustment for effect modification and confounding, tinnitus annoyance was not significantly associated with NFR ( p = 0.79 for tinnitus annoyance)., Conclusions: This study showed that having tinnitus was not associated with a higher NFR. Also, higher levels of tinnitus annoyance were not associated with a higher NFR. NFR was associated with the psychological factors distress, somatization, and depression, which are known to be intricately related to tinnitus. A longitudinal study design is recommended as it can assess the sequence of events, which might help disentangle the association between tinnitus, NFR, and psychological factors., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2022 The Authors. Ear & Hearing is published on behalf of the American Auditory Society, by Wolters Kluwer Health, Inc.)

Objectives: The aim of this study was to modify a speech perception in noise test to assess whether the presence of another individual (copresence), relative to being alone, affected listening performance and effort expenditure. Furthermore, this study assessed if the effect of the other individual's presence on listening effort was influenced by the difficulty of the task and whether participants had to repeat the sentences they listened to or not., Design: Thirty-four young, normal-hearing participants (mean age: 24.7 years) listened to spoken Dutch sentences that were masked with a stationary noise masker and presented through a loudspeaker. The participants alternated between repeating sentences (active condition) and not repeating sentences (passive condition). They did this either alone or together with another participant in the booth. When together, participants took turns repeating sentences. The speech-in-noise test was performed adaptively at three intelligibility levels (20%, 50%, and 80% sentences correct) in a block-wise fashion. During testing, pupil size was recorded as an objective outcome measure of listening effort., Results: Lower speech intelligibility levels were associated with increased peak pupil dilation (PPDs) and doing the task in the presence of another individual (compared with doing it alone) significantly increased PPD. No interaction effect between intelligibility and copresence on PPD was found. The results suggested that the change of PPD between doing the task alone or together was especially apparent for people who started the experiment in the presence of another individual. Furthermore, PPD was significantly lower during passive listening, compared with active listening. Finally, it seemed that performance was unaffected by copresence., Conclusion: The increased PPDs during listening in the presence of another participant suggest that more effort was invested during the task. However, it seems that the additional effort did not result in a change of performance. This study showed that at least one aspect of the social context of a listening situation (in this case copresence) can affect listening effort, indicating that social context might be important to consider in future cognitive hearing research., Competing Interests: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie-Sklodowska-Curie grant agreement No 765329. There are no conflicts of interest financially or otherwise., (Copyright © 2021 The Authors. Ear & Hearing is published on behalf of the American Auditory Society, by Wolters Kluwer Health, Inc.)

Previous research has shown a learning effect on speech perception in nonstationary maskers. The present study addressed the time-course of this learning effect and the role of informational masking. To that end, speech reception thresholds (SRTs) were measured for speech in either a stationary noise masker, an interrupted noise masker, or a single-talker masker. The utterance of the single talker was either time-forward (intelligible) or time-reversed (unintelligible), and the sample of the utterance was either frozen (same utterance at each presentation) or random (different utterance at each presentation but from the same speaker). Simultaneously, the pupil dilation response was measured to assess differences in the listening effort between conditions and to track changes in the listening effort over time within each condition. The results showed a learning effect for all conditions but the stationary noise condition-that is, improvement in SRT over time while maintaining equal pupil responses. There were no significant differences in pupil responses between conditions despite large differences in the SRT. Time reversal of the frozen speech affected neither the SRT nor pupil responses.

Purpose The pupil dilation response is sensitive not only to auditory task demand but also to cognitive conflict. Conflict is induced by incompatible trials in auditory Stroop tasks in which participants have to identify the presentation location (left or right ear) of the words "left" or "right." Previous studies demonstrated that the compatibility effect is reduced if the trial is preceded by another incompatible trial (conflict adaptation). Here, we investigated the influence of hearing status on cognitive conflict and conflict adaptation in an auditory Stroop task. Method Two age-matched groups consisting of 32 normal-hearing participants ( M age = 52 years, age range: 25-67 years) and 28 participants with hearing impairment ( M age = 52 years, age range: 23-64 years) performed an auditory Stroop task. We assessed the effects of hearing status and stimulus compatibility on reaction times (RTs) and pupil dilation responses. We furthermore analyzed the Pearson correlation coefficients between age, degree of hearing loss, and the compatibility effects on the RT and pupil response data across all participants. Results As expected, the RTs were longer and pupil dilation was larger for incompatible relative to compatible trials. Furthermore, these effects were reduced for trials following incompatible (as compared to compatible) trials (conflict adaptation). No general effect of hearing status was observed, but the correlations suggested that higher age and a larger degree of hearing loss were associated with more interference of current incompatibility on RTs. Conclusions Conflict processing and adaptation effects were observed on the RTs and pupil dilation responses in an auditory Stroop task. No general effects of hearing status were observed, but the correlations suggested that higher age and a greater degree of hearing loss were related to reduced conflict processing ability. The current study underlines the relevance of taking into account cognitive control and conflict adaptation processes.

The pupil dilation response is sensitive both to listening effort and the emotional significance of a task. We aimed to assess the influence of evaluative feedback on the pupil dilation response using a speech reception threshold (SRT) task. Besides the pupil dilation response, we acquired subjective ratings and two physiological biomarkers sensitive to stress: cortisol and alpha-amylase levels as determined in saliva samples. We included 34 participants with normal hearing (mean age = 52 years, age range 25-67 years) and 29 age-matched participants with mild-to-moderate hearing loss (mean age = 52 years, age range 23-64 years). Half of the participants performed a standard SRT test without feedback, and the other half performed an SRT test in which they did receive feedback and were urged to perform better. The SRT conditions targeted 50% and 71% correct reception of the sentences. Pupil size was recorded and saliva samples were obtained and participants rated their experience of the task. Participants with hearing loss performed more poorly on the SRT test than participants with normal hearing participants receiving feedback had better SRTs in the 71% intelligibility condition and higher peak pupil dilation in both intelligibility conditions than participants who did not receive feedback, irrespective of hearing status. Saliva cortisol level and alpha-amylase activity reflected the usual diurnal patterns but showed no effects of hearing status or feedback. Finally, participants who received feedback experienced more difficulties than those who did not receive feedback, irrespective of hearing status. This study underlines the importance of taking into account the influence of task instructions and feedback in a speech perception task as these factors may influence the experienced difficulties, listening effort, and task performance., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: We examined the influence of impaired processing (audibility and suprathreshold processes) on speech recognition in cases of sensorineural hearing loss. The influence of differences in central, or top-down, processing was reduced by comparing the performance of both ears in participants with a unilateral hearing loss (UHL). We examined the influence of reduced audibility and suprathreshold deficits on speech recognition in quiet and in noise., Design: We measured speech recognition in quiet and stationary speech-shaped noise with consonant-vowel-consonant words and digital triplets in groups of adults with UHL (n = 19), normal hearing (n = 15), and bilateral hearing loss (n = 9). By comparing the scores of the unaffected ear (UHL+) and the affected ear (UHL-) in the UHL group, we were able to isolate the influence of peripheral hearing loss from individual top-down factors such as cognition, linguistic skills, age, and sex., Results: Audibility is a very strong predictor for speech recognition in quiet. Audibility has a less pronounced influence on speech recognition in noise. We found that, for the current sample of listeners, more speech information is required for UHL- than for UHL+ to achieve the same performance. For digit triplets at 80 dBA, the speech recognition threshold in noise (SRT) for UHL- is on average 5.2 dB signal to noise ratio (SNR) poorer than UHL+. Analysis using the speech intelligibility index (SII) indicates that on average 2.1 dB SNR of this decrease can be attributed to suprathreshold deficits and 3.1 dB SNR to audibility. Furthermore, scores for speech recognition in quiet and in noise for UHL+ are comparable to those of normal-hearing listeners., Conclusions: Our data showed that suprathreshold deficits in addition to audibility play a considerable role in speech recognition in noise even at intensities well above hearing threshold.

Purpose: This letter to the editor is in response to a research note by Jin, Kates, and Arehart (2017), "Sensitivity of the Speech Intelligibility Index to the Assumed Dynamic Range," published in June 2017 by the Journal of Speech, Language, and Hearing Research., Conclusion: The authors argue that the approach and line of reasoning in the Jin et al. (2017) research note suggest new findings but do not lead to essentially new insights.

Speech comprehension depends on the successful operation of a network of brain regions. Processing of degraded speech is associated with different patterns of brain activity in comparison with that of high-quality speech. In this exploratory study, we studied whether processing degraded auditory input in daily life because of hearing impairment is associated with differences in brain volume. We compared T1-weighted structural magnetic resonance images of 17 hearing-impaired (HI) adults with those of 17 normal-hearing (NH) controls using a voxel-based morphometry analysis. HI adults were individually matched with NH adults based on age and educational level. Gray and white matter brain volumes were compared between the groups by region-of-interest analyses in structures associated with speech processing, and by whole-brain analyses. The results suggest increased gray matter volume in the right angular gyrus and decreased white matter volume in the left fusiform gyrus in HI listeners as compared with NH ones. In the HI group, there was a significant correlation between hearing acuity and cluster volume of the gray matter cluster in the right angular gyrus. This correlation supports the link between partial hearing loss and altered brain volume. The alterations in volume may reflect the operation of compensatory mechanisms that are related to decoding meaning from degraded auditory input.

For people with hearing difficulties, following a conversation in a noisy environment requires substantial cognitive processing, which is often perceived as effortful. Recent studies with normal hearing (NH) listeners showed that the pupil dilation response, a measure of cognitive processing load, is affected by 'attention related' processes. How these processes affect the pupil dilation response for hearing impaired (HI) listeners remains unknown. Therefore, the current study investigated the effect of auditory attention on various pupil response parameters for 15 NH adults (median age 51 yrs.) and 15 adults with mild to moderate sensorineural hearing loss (median age 52 yrs.). Both groups listened to two different sentences presented simultaneously, one to each ear and partially masked by stationary noise. Participants had to repeat either both sentences or only one, for which they had to divide or focus attention, respectively. When repeating one sentence, the target sentence location (left or right) was either randomized or blocked across trials, which in the latter case allowed for a better spatial focus of attention. The speech-to-noise ratio was adjusted to yield about 50% sentences correct for each task and condition. NH participants had lower ('better') speech reception thresholds (SRT) than HI participants. The pupil measures showed no between-group effects, with the exception of a shorter peak latency for HI participants, which indicated a shorter processing time. Both groups showed higher SRTs and a larger pupil dilation response when two sentences were processed instead of one. Additionally, SRTs were higher and dilation responses were larger for both groups when the target location was randomized instead of fixed. We conclude that although HI participants could cope with less noise than the NH group, their ability to focus attention on a single talker, thereby improving SRTs and lowering cognitive processing load, was preserved. Shorter peak latencies could indicate that HI listeners adapt their listening strategy by not processing some information, which reduces processing time and thereby listening effort., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

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., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

This study aimed to determine the predictors of entering a hearing aid evaluation period (HAEP) using a prospective design drawing on the health belief model and the transtheoretical model. In total, 377 older persons who presented with hearing problems to an Ear, Nose, and Throat specialist ( n = 110) or a hearing aid dispenser ( n = 267) filled in a baseline questionnaire. After 4 months, it was determined via a telephone interview whether or not participants had decided to enter a HAEP. Multivariable logistic regression analyses were applied to determine which baseline variables predicted HAEP status. A priori, candidate predictors were divided into 'likely' and 'novel' predictors based on the literature. The following variables turned out to be significant predictors: more expected hearing aid benefits, greater social pressure, and greater self-reported hearing disability. In addition, greater hearing loss severity and stigma were predictors in women but not in men. Of note, the predictive effect of self-reported hearing disability was modified by readiness such that with higher readiness, the positive predictive effect became stronger. None of the 'novel' predictors added significant predictive value. The results support the notion that predictors of hearing aid uptake are also predictive of entering a HAEP. This study shows that some of these predictors appear to be gender specific or are dependent on a person's readiness for change. After assuring the external validity of the predictors, an important next step would be to develop prediction rules for use in clinical practice, so that older persons' hearing help-seeking journey can be facilitated.

An important aspect of hearing is the degree to which listeners have to deploy effort to understand speech. One promising measure of listening effort is task-evoked pupil dilation. Here, we use functional magnetic resonance imaging (fMRI) to identify the neural correlates of pupil dilation during comprehension of degraded spoken sentences in 17 normal-hearing listeners. Subjects listened to sentences degraded in three different ways: the target female speech was masked by fluctuating noise, by speech from a single male speaker, or the target speech was noise-vocoded. The degree of degradation was individually adapted such that 50% or 84% of the sentences were intelligible. Control conditions included clear speech in quiet, and silent trials. The peak pupil dilation was larger for the 50% compared to the 84% intelligibility condition, and largest for speech masked by the single-talker masker, followed by speech masked by fluctuating noise, and smallest for noise-vocoded speech. Activation in the bilateral superior temporal gyrus (STG) showed the same pattern, with most extensive activation for speech masked by the single-talker masker. Larger peak pupil dilation was associated with more activation in the bilateral STG, bilateral ventral and dorsal anterior cingulate cortex and several frontal brain areas. A subset of the temporal region sensitive to pupil dilation was also sensitive to speech intelligibility and degradation type. These results show that pupil dilation during speech perception in challenging conditions reflects both auditory and cognitive processes that are recruited to cope with degraded speech and the need to segregate target speech from interfering sounds., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: A common method to assess the functional benefit of hearing aids is by measuring the performance-intensity curve of single words in quiet with and without hearing aids. Currently, virtually all hearing aids use signal processing, which may have a marked effect on gain as a function of time. Thus, hearing-aid behavior may be different for a word presented in isolation compared to the same word preceded by a carrier phrase, which is a closer replication of natural conversation. The present research was conducted to assess this difference., Design: In a hearing-aid test box, speech materials were routed through hearing aids and the output was recorded with a 2cc coupler., Study Sample: Seven different hearing aids were programmed according to the manufacturer's fitting rules, using a given hearing loss., Results: Depending on the hearing aid, and the hearing-aid setting, differences in the overall level of the hearing-aid processed words ranged from 1.5 to 3.5 dB. Differences were due to slow attack times in amplitude compression., Conclusions: Although differences were small for most hearing aids, the use of a carrier phrase should be considered in speech intelligibility tests to ensure that hearing-aid performance closer reflects that in real life.

The extended speech intelligibility index (ESII) model (Rhebergen et al, 2006) forms an upgrade to the conventional speech intelligibility index model. For normal-hearing listeners the ESII model is able to predict the speech reception threshold (SRT) in both stationary and non-stationary noise maskers. In this paper, a first attempt is made to evaluate the ESII with SRT data obtained by de Laat and Plomp (1983), and Versfeld and Dreschler (2002) of hearing-impaired listeners in stationary, 10-Hz interrupted, and non-stationary speech-shaped noise measured at different noise levels. The results show that the ESII model is able to describe the SRT in different non-stationary noises for normal-hearing listeners at different noise levels reasonably well. However, the ESII model is less successful in the case of predicting the SRT in non-stationary noise for hearing-impaired subjects. As long as the present audibility models cannot describe the auditory processing in a listener with cochlear hearing loss accurately, it is difficult to distinguish between raised SRTs due to supra-threshold deficits or factors such as cognition, age, and language skills.

Changes in the speech reception threshold (SRT) after amplitude compression of speech or speech in noise may be due to changes in the dynamic range of the speech signal. However, current models set up to predict the speech intelligibility consider the dynamic range of speech to be fixed regardless of the type of compression. The present paper describes two experiments with normal-hearing subjects to examine the effect of the dynamic range on the SRT in stationary and interrupted noise after wide dynamic range compression. The dynamic range has been varied by compression or expansion of only the speech signal, leaving the masking noise unaltered, or by compression or expansion of the mixed speech-in-noise signal. The results show that compression affects the SRT, both in a positive or a negative direction, not only due to dynamic range but also due to distortion of the speech signal.

Traditionally, the speech reception threshold (SRT) for sentences in noise is measured in stationary speech-shaped noise; however, non-stationary masking noises are gradually becoming more common. A previous study by Rhebergen et al. (2006) suggested that a learning effect might be present for the SRT in interrupted noise but not in stationary noise. The current study tested if a stable SRT for female or male speech is reached by determining SRTs in listeners with normal hearing in either stationary or 8-Hz interrupted noise after five replications. Contrary to repeated SRT measurements in stationary noise, a significant improvement was observed for SRTs in interrupted noise with replication. For both speech materials, after five replications, the SRT in interrupted noise improved about 3 to 4 dB in comparison to the first SRT. Stable thresholds seem to be reached after about two replications. This experiment shows that there is a substantial learning effect present in SRT measurements with interrupted noise but not in stationary noise. With non-stationary noise, it is recommended to include a repeated measures design.

The extension to the speech intelligibility index (SII; ANSI S3.5-1997 (1997)) proposed by Rhebergen and Versfeld [Rhebergen, K.S., and Versfeld, N.J. (2005). J. Acoust. Soc. Am. 117(4), 2181-2192] is able to predict for normal-hearing listeners the speech intelligibility in both stationary and fluctuating noise maskers with reasonable accuracy. The extended SII model was validated with speech reception threshold (SRT) data from the literature. However, further validation is required and the present paper describes SRT experiments with nonstationary noise conditions that are critical to the extended model. From these data, it can be concluded that the extended SII model is able to predict the SRTs for the majority of conditions, but that predictions are better when the extended SII model includes a function to account for forward masking.

The SII model in its present form (ANSI S3.5-1997, American National Standards Institute, New York) can accurately describe intelligibility for speech in stationary noise but fails to do so for nonstationary noise maskers. Here, an extension to the SII model is proposed with the aim to predict the speech intelligibility in both stationary and fluctuating noise. The basic principle of the present approach is that both speech and noise signal are partitioned into small time frames. Within each time frame the conventional SII is determined, yielding the speech information available to the listener at that time frame. Next, the SII values of these time frames are averaged, resulting in the SII for that particular condition. Using speech reception threshold (SRT) data from the literature, the extension to the present SII model can give a good account for SRTs in stationary noise, fluctuating speech noise, interrupted noise, and multiple-talker noise. The predictions for sinusoidally intensity modulated (SIM) noise and real speech or speech-like maskers are better than with the original SII model, but are still not accurate. For the latter type of maskers, informational masking may play a role.

A conventional measure to determine the ability to understand speech in noisy backgrounds is the so-called speech reception threshold (SRT) for sentences. It yields the signal-to-noise ratio (in dB) for which half of the sentences are correctly perceived. The SRT defines to what degree speech must be audible to a listener in order to become just intelligible. There are indications that elderly listeners have greater difficulty in understanding speech in adverse listening conditions than young listeners. This may be partly due to the differences in hearing sensitivity (presbycusis), hence audibility, but other factors, such as temporal acuity, may also play a significant role. A potential measure for the temporal acuity may be the threshold to which speech can be accelerated, or compressed in time. A new test is introduced where the speech rate is varied adaptively. In analogy to the SRT, the time-compression threshold (or TCT) then is defined as the speech rate (expressed in syllables per second) for which half of the sentences are correctly perceived. In experiment I, the TCT test is introduced and normative data are provided. In experiment II, four groups of subjects (young and elderly normal-hearing and hearing-impaired subjects) participated, and the SRT's in stationary and fluctuating speech-shaped noise were determined, as well as the TCT. The results show that the SRT in fluctuating noise and the TCT are highly correlated. All tests indicate that, even after correction for the hearing loss, elderly normal-hearing subjects perform worse than young normal-hearing subjects. The results indicate that the use of the TCT test or the SRT test in fluctuating noise is preferred over the SRT test in stationary noise.

A method is described to select sentence materials for efficient measurement of the speech reception threshold (SRT). The first part of the paper addresses the creation of the sentence materials, the recording procedure, and a listening experiment to evaluate the new speech materials. The result is a set of 1272 sentences, where every sentence has been uttered by two male and two female speakers. In the second part of the paper, a method is described to select subsets with properties that are desired for an efficient measurement of the SRT. For two speakers, this method has been applied to obtain two subsets for measurement of the SRT in stationary noise with the long-term average spectrum of speech. Lastly, a listening experiment has been conducted where the two subsets (each comprising 39 lists of 13 sentences each) are directly compared to the existing sets of Plomp and Mimpen [Audiology 18, 43-52 (1979)] and Smoorenburg [J. Acoust. Soc. Am. 91, 421-437 (1992)]. One of the outcomes is that the newly developed sets can be considered as equivalent to these existing sets.

In order to assess the relative importance of various signal processing algorithms and distortions on hearing-aid preference, male and female speech was manipulated in a number of ways and subsequently presented to normal-hearing and hearing-impaired subjects (the latter having a mild sensorineural high-frequency hearing loss). Signal manipulations were artificial (e.g., filtering, compression, peak clipping, or adding noise) or were actual dummy-head recordings of five different hearing aids. Listeners judged the sounds in a pairwise-comparison format. Their task was to indicate the "hearing aid" they would prefer assuming they had to wear it all day. The data were analyzed with multidimensional scaling techniques; Principal Components Analysis revealed that the first two dimensions on which preference judgments were based, can be interpreted as (1) intelligibility or clarity, and (2) distinction between signal distortion and added background distortion. Furthermore, the results showed that normal-hearing subjects generally preferred the original signal, whereas hearing-impaired subjects were inclined to choose the signals with a high-frequency emphasis. Severe band-pass filtering or low-frequency emphasis were disliked, as was to be expected. Surprisingly, however, a soft background noise (S/N ratio of 25 dB) was often among the least preferred of all signals. The differences in preference between the five hearing aids were small, but consistent. For hearing-impaired subjects, hearing-aid ordering could be accounted for by the amount of low-frequency cutoff; for normal-hearing subjects both high- and low-frequency cutoff played a role. Results of a retest experiment with normal-hearing subjects, about one year later, showed that subjects' criteria remain remarkably stable.

Discrimination experiments were performed for a change in the spectral shape of noise bands. The subject's task was to discriminate noise bands with a positive spectral slope from those with a negative spectral slope. Thresholds were measured at several bandwidths and center frequencies, as well as for several noise samples. Experiments were performed while roving the overall intensity. At a fixed center frequency of 1 kHz, sensitivity was best for bandwidths of 3-6 semitones (ST). At larger bandwidths, thresholds increased only slowly. At a fixed bandwidth of 1 ST, threshold hardly changed as a function of the center frequency. At a fixed bandwidth of 58 Hz, threshold was lowest near 500-1000 Hz. Model calculations show that the EWAIF model [Feth, Percept. Psychophys. 15, 375-378 (1974)] can account for the present results if the signal's bandwidth does not exceed 1 ST. The IWAIF model [Anantharaman et al., J. Acoust. Soc. Am. 94, 723-729 (1993)] can account for the present results only if the signal's bandwidth is smaller than 1 ST but larger than about 25 Hz. Results obtained with broadband signals could be described only qualitatively with the multichannel model [Durlach et al., J. Acoust. Soc. Am. 80, 63-72 (1986)]. Then, the model needs the assumption that either the output of the different frequency bands cannot be optimally combined, or that only two bands are used in the discrimination process. The present results are compared with those obtained with two-tone complexes measured under identical conditions [Versfeld and Houtsma, J. Acoust. Soc. Am. 98, 807-816 (1995)].

In a laboratory experiment, the relationship between the annoyance caused by sounds of tracked and wheeled vehicles was investigated. Sounds of various vehicles, ranging from a main battle tank (MBT) to a passenger car, were recorded at several distances. Subjects were presented with these sounds and were asked to judge the annoyance if they were exposed to them at home on a regular basis. Overall, sounds emanated from military tracked vehicles were judged to be less annoying than civil passenger cars, provided that the indoor A-weighted sound-exposure levels (ASELs) were the same. It should be noted that receiver distance and operating conditions were not specifically matched for military and civil vehicles but were chosen to represent typical ranges of values found in practice. For steady-speed conditions, the sounds were judged to be equally annoying if the (indoor) ASELs of the tracked armored personnel carrier (APC) and the MBT exceeded that of a passenger car by 5 and 10 dB, respectively. In specific driving conditions such as alternate accelerations and decelerations, however, these differences were smaller. For ASELs below 55 dB, passenger cars were found to be more annoying than heavier wheeled vehicles, such as a bus or a truck with a trailer. The data indicate that the difference between the high-frequency part and the low-frequency part of the spectrum might play a role in the annoyance. With respect to noise-zoning procedures it is highly interesting that the outdoor ASEL could predict the annoyance, as rated indoors, better than could any indoor noise measure. The 5- and 10-dB bonuses to the indoor level of the APC and the MBT, respectively, were reduced to 1 and 3 dB if the dose was measured outdoors.

In this paper we derive the optimum (likelihood-ratio) decision statistic for a same-different paradigm. The likelihood ratio is dependent on the degree of correlation between the two observations on each trial. For the two extreme cases in which the observations are either independent or highly correlated, the optimum decision rule is identical to each of two previously suggested decision rules. For these two cases, the receiver-operating characteristic (ROC) curves are calculated. Finally, an experimental procedure is suggested for assessing the decision rule actually used by the observer in a same-different task.

This paper presents the optimum decision rule for an m-interval oddity task in which m-1 intervals contain the same signal and one is different or odd. The optimum decision rule depends on the degree of correlation among observations. The present approach unifies the different strategies that occur with "roved" or "fixed" experiments (Macmillan & Creelman, 1991, p. 147). It is shown that the commonly used decision rule for an m-interval oddity task corresponds to the special case of highly correlated observations. However, as is also true for the same-different paradigm, there exists a different optimum decision rule when the observations are independent. The relation between the probability of a correct response and d' is derived for the three-interval oddity task. Tables are presented of this relation for the three-, four-, and five-interval oddity task. Finally, an experimental method is proposed that allows one to determine the decision rule used by the observer in an oddity experiment.

Discrimination experiments were performed for changes in the amplitude of two-tone complexes. Thresholds were measured, among other things, as a function of bandwidth and center frequency. Usually, the overall intensity was roved in each and every presentation to prevent subjects from using loudness cues. The results show that changes in the spectral shape of broadband two-tone complexes can be perceived with and without a roving intensity level. For narrow-band signals, attempts have been made to explain the results in terms of the EWAIF model [Feth, Percept. Psychophys. 15, 375-378 (1974)]. This model could account for the data for signal bandwidths of 1 semitone or less. Modified EWAIF models did not yield better predictions. Thresholds for a change in the spectral shape were measured as a function of sensation level. The "near-miss" to Weber's law was not observed. This result is consistent with excitation pattern models.

Amplitude changes of the spectral components of a complex tone, relative to each other, are usually well perceived, even if the over-all intensity is kept fixed. Three experiments are reported: Experiment 1 dealt with the detectability of amplitude changes in two-tone complexes of fixed frequencies. Experiment 2 examined detection of slope changes in ramp-shaped spectral envelopes of two- and three-tone complexes as a function of spectral spacing. As a control experiment for some conditions a roving intensity level was used. Experiment 3 investigated the detectability of changes in the spectral slope of multi-tone complexes as a function of the number of components. The results of the experiments show that detection of spectral changes in a sound is strongly dependent on the frequency spacing of the components. It is concluded that the auditory system is capable of comparing the relative energy distributions over different critical bands. Within a critical band there exists an optimum frequency separation with respect to the detection of relative amplitude change.

Perception of global pitch motion was studied through psychoacoustic experiments with random chord sequences. Chords contained either six or eight (fixed) tone elements, being sinusoidal, sawtooth-like, or Shepard tones, which were either on or off according to a probability controlled by the experimenter. Sequences of 2, 4, 5, or 8 chords were used. Identification by subjects of the perceived direction of overall pitch motion (up or down) was found to be well accounted for by a model in which the ultimate pitch motion percept is given by a sum of contributions from selected element transitions--that is, transitions between adjoining tone elements in successive time frames only. In its simplest form, this dipole contribution model has only one free parameter, the perceptual noise for an element transition, which was estimated for various acoustic tone representations and chord arrangements. Results of two experiments, which were carried out independently in two different laboratories, are reported.