Decline of speech understanding and auditory thresholds in the elderly

Association between hearing status and social participation in Japanese older adults: A cross-sectional study from the Japan gerontological evaluation study

PURPOSE

Hearing is known to decline with age. As sensitivity to speech declines, conversation becomes more difficult and social interactions are affected, resulting in increased risk of cognitive decline. This study aimed to examine the relationship between hearing status and social participation.

MATERIALS AND METHODS

The study included 21,117 adults aged 65 years or older who responded to a survey in 2019. The survey asked participants about their hearing status and how frequently they participated in certain social activities.

RESULTS

The analysis of the relationship between degree of hearing and social activity showed lower hearing status odds ratios for those who participated more frequently in social activities compared to those who participated less frequently. The odds ratios were as follows, hobby clubs (OR 0.81, 95%CI 0.78-0.84), activities such as teaching skills or passing on experiences to others (OR 0.69, 95%CI 0.65-0.75), and meeting with friends (OR 0.77, 95%CI 0.74-0.79). Compared to those who did not participate in social activities, those who participated in three or more types of groups had significantly lower hearing impairment (OR 0.75, 95% CI 0.72-0.79).

CONCLUSION

Hearing impairment was shown to inhibit participation in activities, including those that require communication with multiple people or smooth communication, those that involve a wide range of ages, and those that involve work and movement. Hearing impairment should be identified and addressed in its early stages to prevent its negative impact on social participation.

Effect of Age on Speech Perception in Noise Abilities Across Different Stimulus

Various factors influence speech perception in noise (SPIN): age, hearing loss, cognition, background noise, stimulus redundancy, type of stimulus used, and signal-to-noise ratio. The effect of age on SPIN with different stimuli is yet to be validated in the literature. This study aims to study the effect of age on SPIN results across different stimuli. The study is a cross-sectional study with ninety participants with normal hearing ability. All participants in the study were equally divided into three groups: the children's group aged 8 to 12 years, the adult group aged 18 to 30, and the older adult group aged 55 to 72 years. Speech perception in the background of Kannada speech babble was assessed across three stimuli: monosyllables (CV), phonemically balanced Kannada words, and Kannada sentences. The stimulus was presented at 60 dBSPL binaurally through a calibrated headphone at 0 dB SNR. The result indicated a significant main effect of age on SPIN across syllables, words, and sentences. Further, Mann-Whitney test results revealed a statistically significant difference between the SPIN scores of children and adults for syllables, words, and sentences. Also, a statistical difference was noted in SPIN scores between adults and older adults for syllables, words, and sentences. However, statistical differences between children and older adults were seen only for syllables. The trend showed that the SPIN scores for syllables, words, and sentences improve from childhood to adulthood, while scores deteriorate from the adult to older adult group. A similar trend was seen for all three stimulus types. However, the reduction in the SPIN score using syllables in the older adult group was more noticeable than words and sentences. It can be concluded that there is an effect of age on SPIN abilities across different stimuli. It highlights the importance of age-appropriate SPIN normative for various stimuli.

Cognitive control in age-related hearing loss: A narrative review

Recent evidence suggests links between hearing loss and cognitive impairment in older adults with peripheral age-related hearing loss (ARHL). Earliest cognitive changes have been observed in cognitive control; however, a cohesive account of cognitive control alterations in older adults with peripheral ARHL is lacking. Cognitive control refers to cognitive processes that manage and regulate one's behavior to achieve desired goals. This review summarizes behavioral evidence on alterations in three cognitive control processes, including cognitive flexibility, inhibitory control, and working memory updating, in individuals with ARHL. Of the three processes, cognitive flexibility and working memory updating have been most extensively studied, with relatively fewer studies examining inhibitory control. Most consistent evidence is observed for long-term changes in cognitive flexibility, particularly in individuals with greater severity of ARHL. Equivocal evidence is seen for alterations in inhibitory control and working memory updating, with various factors contributing to inconsistencies across studies. Our review summarizes the emerging body of research on cognitive control in individuals with ARHL to guide future work in this area and considerations related to the management of cognitive issues in this population.

Development of the hearing-related quality of life questionnaire for auditory-visual, cognitive and psychosocial functioning (hAVICOP)

INTRODUCTION

There is a need for a validated and standardized self-assessment instrument to assess the subjective effect of hearing aid (HA) use and/or cochlear implantation (CI) on different aspects of functioning in daily life. The aim of this study was to develop a new holistic Patient Reported Outcome Measure (PROM) to assess hearing-related quality of life. The new PROM is titled the hearing-related quality of life questionnaire for Auditory-VIsual, COgnitive and Psychosocial functioning (hAVICOP).

METHODS

A conceptual framework was set up and test items were prepared per domain. Preliminary testing involved a semi-structured interview-based assessment in normal-hearing and hearing-impaired adults and an expert panel. For the further psychometric evaluation, a new sample of 15 adult HA users, 20 adult CI users and 20 normal-hearing adults filled in the refined version of the hAVICOP, the Speech, Spatial and Qualities of Hearing Scale, the Nijmegen Cochlear Implant Questionnaire and the TNO-AZL Questionnaire for Adult's Health-Related Quality of Life. Based on these results, a factor analysis was conducted and internal consistency, discriminant validity and concurrent construct validity were determined.

RESULTS

The final version of the hAVICOP consists of three domains for hearing-related quality of life: (1) auditory-visual functioning, (2) cognitive functioning, and (3) psychosocial functioning. A sufficient internal consistency was found, and discriminant validity and concurrent construct validity were good.

CONCLUSIONS

A new PROM to assess hearing-related quality of life was developed, named the hAVICOP. In the future the validity and reliability should be examined further.

The significance of right ear auditory processing to balance

Although the association between balance and hearing thresholds at different frequencies in the right/left ear is crucial, it has received scant empirical attention. Balance is widely ignored when evaluating hearing in adults. This study examined the relative contribution of left versus right ear hearing at different frequencies to balance, and the mediating role of suprathreshold speech perception on age-balance associations. Pure tone hearing thresholds (500-4000 Hz), suprathreshold speech perception, balance, and risk of falling were evaluated in 295 adults. The results indicate that the right ear contributes more to balance than the left ear. This might imply dominance of the left hemisphere in processing hearing cues for balance. Frequencies within the speech range (500/1000/2000 Hz) were correlated with balance and mediated the interaction between age and balance. These results should be considered when tailoring hearing and balance rehabilitation programs.

Plastic changes in speech perception in older adults with hearing impairment following hearing aid use: a systematic review

OBJECTIVE

Whether hearing aid use in older adults modifies speech perception over time is not clear. To address this question, we systematically reviewed studies in which older first-time hearing aid users and controls were followed over time.

DESIGN

The review was pre-registered in PROSPERO and performed in accordance with the statement on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The question, inclusion and exclusion criteria were defined using the Population, Intervention, Control, Outcomes and Study design (PICOS) framework. Studies with no controls, studies in which participants and controls were tested at only one-time point, with no follow-up and no pre-fitting measures, or when outcome measures did not include speech measures, were excluded.

STUDY SAMPLE

6113 studies were screened, out of which 12 studies, published between 1996 and 2021, met the inclusion and exclusion criteria and were included in the final review.

RESULTS

9 of the 12 studies found evidence for amplification-induced auditory plasticity in older adults, expressed in improved speech perception.

CONCLUSIONS

The results suggest amplification-induced improvements in speech perception over time, but findings should be interpreted with caution because overall improvements were small, and the studies' quality was moderate.

Neanderthals and Homo sapiens had similar auditory and speech capacities

The study of audition in fossil hominins is of great interest given its relationship with intraspecific vocal communication. While the auditory capacities have been studied in early hominins and in the Middle Pleistocene Sima de los Huesos hominins, less is known about the hearing abilities of the Neanderthals. Here, we provide a detailed approach to their auditory capacities. Relying on computerized tomography scans and a comprehensive model from the field of auditory bioengineering, we have established sound power transmission through the outer and middle ear and calculated the occupied bandwidth in Neanderthals. The occupied bandwidth is directly related to the efficiency of the vocal communication system of a species. Our results show that the occupied bandwidth of Neanderthals was greater than the Sima de los Huesos hominins and similar to extant humans, implying that Neanderthals evolved the auditory capacities to support a vocal communication system as efficient as modern human speech.

Psychometric function for speech-in-noise tests accounts for word-recognition deficits in older listeners

Speech-in-noise (SIN) understanding in older age is affected by hearing loss, impaired central auditory processing, and cognitive deficits. SIN-tests measure these factors' compound effects by a speech reception threshold, defined as the signal-to-noise ratio required for 50% word understanding (SNR50). This study compared two standard SIN tests, QuickSIN (n = 354) in young and older adults and BKB-SIN (n = 139) in older adults (>60 years). The effects of hearing loss and age on SIN understanding were analyzed to identify auditory and nonauditory contributions to SIN loss. Word recognition in noise was modelled with individual psychometric functions using a logistic fit with three parameters: the midpoint (SNRα), slope (β), and asymptotic word-recognition deficit at high SNR (λ). The parameters SNRα and λ formally separate SIN loss into two components. SNRα characterizes the steep slope of the psychometric function at which a slight SNR increase provides a considerable improvement in SIN understanding. SNRα was discussed as being predominantly affected by audibility and low-level central auditory processing. The parameter λ describes a shallow segment of the psychometric function at which a further increase in the SNR provides modest improvement in SIN understanding. Cognitive factors in aging may contribute to the SIN loss indicated by λ.

The Effect of Cognition on the Aided Benefit in Terms of Speech Understanding and Listening Effort Obtained With Digital Hearing Aids: A Systematic Review

Purpose Hearing aids are the primary rehabilitation devices used to compensate for presbycusis, though large intersubject variability in hearing aid benefit has been reported. This systematic review aimed to investigate how intersubject differences in cognition could influence the aided benefit for speech understanding and listening effort with bilateral digital hearing aids. Method Articles were selected through systematic searches in MEDLINE, Embase, Central, and reference lists. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Results The initial search resulted in 1,092 unique hits, of which 16 were included. The effect of cognition on the aided benefit in terms of speech understanding and listening effort was examined in 12 and four studies, respectively. The aided speech and listening effort benefit obtained from hearing aid use in general or from a specific digital feature (i.e., microphone directionality, noise reduction, amplitude compression, and frequency compression) was associated with four cognitive functions (i.e., working memory, processing speed, selective attention, and executive functions). Conclusions Hearing aid users with poorer cognitive functioning derived more aided benefit in terms of speech understanding from hearing aid settings facilitating the matching process between the incoming auditory signal and representations stored in long-term memory. However, since the number of included studies was limited, this trend should be interpreted with caution. Supplemental Material https://doi.org/10.23641/asha.13626509.

Unmasking the Difficulty of Listening to Talkers With Masks: lessons from the COVID-19 pandemic

Interactions with talkers wearing face masks have become part of our daily routine since the beginning of the COVID-19 pandemic. Using an on-line experiment resembling a video conference, we examined the impact of face masks on speech comprehension. Typical-hearing listeners performed a speech-in-noise task while seeing talkers with visible lips, talkers wearing a surgical mask, or just the name of the talker displayed on screen. The target voice was masked by concurrent distracting talkers. We measured performance, confidence and listening effort scores, as well as meta-cognitive monitoring (the ability to adapt self-judgments to actual performance). Hiding the talkers behind a screen or concealing their lips via a face mask led to lower performance, lower confidence scores, and increased perceived effort. Moreover, meta-cognitive monitoring was worse when listening in these conditions compared with listening to an unmasked talker. These findings have implications on everyday communication for typical-hearing individuals and for hearing-impaired populations.

Cognitive Flexibility and Inhibition in Individuals with Age-Related Hearing Loss

Growing evidence suggests alterations in cognitive control processes in individuals with varying degrees of age-related hearing loss (ARHL); however, alterations in those with unaided mild ARHL are understudied. The current study examined two cognitive control processes, cognitive flexibility, and inhibition, in 21 older adults with unaided mild ARHL and 18 age- and education-matched normal hearing (NH) controls. All participants underwent comprehensive audiological and cognitive evaluations including Trail Making Test-B, Verbal Fluency, Stroop, and two Go/NoGo tasks. Group differences in cognitive flexibility and inhibition as well as associations between peripheral and central hearing ability and measures of cognitive flexibility and inhibition were investigated. Findings revealed that the ARHL group took significantly longer to complete the Stroop task and had higher error rates on NoGo trials on both Go/NoGo tasks relative to the NH controls. Additionally, poorer peripheral and central hearing were associated with poorer cognitive flexibility and inhibitory control. Our findings suggest slower and more inefficient inhibitory control in the mild ARHL group relative to the NH group and add to decades of research on the association between hearing and cognition.

Evaluation of the efficacy of hearing aids in older adults: a multiparametric longitudinal study protocol

Background

Prevalence of hearing loss increases with age. Its estimated prevalence is 40–50 % in people over 75 years of age. Recent studies agree that declinein hearing threshold contribute to deterioration in sociality, sensitivity, cognition, and quality of life for elderly subjects.

The aim of the study presented in this paper is to verify whether or not rehabilitation using first time applied Hearing Aids (HA) in a cohort of old people with hearing impairment improves both speech perception in a noisy environment over time and the overall health-related quality of life.

Methods

The monocentric, prospective, repeated measurements, single-subject, clinical observational study is to recruit 100 older adults, first-time HA recipients (≥ 65 years).The evaluation protocol is designed to analyze changes in specific measurement tools a year after the first HA usage in comparison with the evaluation before HA fitting.

Evaluations will consist of multiparametric details collected through self-report questionnaires completed by the recipients and a series of commonly used audiometric measures and geriatric assessment tools. The primary indicator of changes in speech perception in noise to be used is the Italian version of Oldenburg Satz (OLSA) test whereas the indicator of changes in overall quality of life will be the Assessment of Quality of Life (AQoL) and Hearing Handicap Inventory for the Elderly (HHIE) questionnaires. The Montreal Cognitive Assessment (MoCA) will help in screening the cognitive state of the subjects.

Discussion

The protocol is designed to make use of measurement tools that have already been applied to the hearing-impaired population in order to compare the effects of HA rehabilitation in the older adults immediately before first HA usage (Pre) and after 1 year of experience (Post). This broad approach will lead to a greater understanding of how useful hearing influences the quality of life in older individuals, and therefore improves potentials for healthy aging. The data is to be analyzed by using an intrasubject endpoint comparison. Outcomes will be described and analyzed in detail.

Trial registration

This research was retrospectively registered underno. NCT04333043at ClinicalTrials.gov (http://www.clinicaltrials.gov/) on the 26 March 2020. This research has been registered with the Ethics Committee of the Area Vasta Emilia Nord under number 104, date of approval 17/07/2017.

Confidence Limits of Word Identification Scores Derived Using Nonlinear Quantile Regression

The relation between degree of sensorineural hearing loss and maximum speech identification scores (PBmax) is commonly used in audiological diagnosis and rehabilitation. It is important to consider the relation between the degree of hearing loss and the lower boundary of PBmax, as the PBmax varies largely between subjects at a given degree of hearing loss. The present study determines the lower boundary by estimating the lower limit of the one-tailed 95% confidence limit (CL) for a Dantale I, word list, in a large group of young and older subjects with primarily sensorineural hearing loss. PBmax scores were measured using Dantale I, at 30 dB above the speech reception threshold or at the most comfortable level from 1,961 subjects with a wide range of pure-tone averages. A nonlinear quantile regression approach was applied to determine the lower boundary (95% CL) of PBmax scores. At a specific pure-tone average, if the measured PBmax is poorer than the lower boundary (95% CL) of PBmax, it may be considered disproportionately poor.

Encoding of a binaural speech stimulus at the brainstem level in middle-aged adults

OBJECTIVE

Binaural hearing is facilitated by neural interactions in the auditory pathway. Ageing results in impairment of localisation and listening in noisy situations without any significant hearing loss. The present study focused on comparing the binaural encoding of a speech stimulus at the subcortical level in middle-aged versus younger adults, based on speech-evoked auditory brainstem responses.

METHODS

Thirty participants (15 young adults and 15 middle-aged adults) with normal hearing sensitivity (less than 15 dB HL) participated in the study. The speech-evoked auditory brainstem response was recorded monaurally and binaurally with a 40-ms /da/ stimulus. Fast Fourier transform analysis was utilised.

RESULTS

An independent sample t-test revealed a significant difference between the two groups in fundamental frequency (F0) amplitude recorded with binaural stimulation.

CONCLUSION

The present study suggested that ageing results in degradation of F0 encoding, which is essential for the perception of speech in noise.

Topic Modeling for Analyzing Patients' Perceptions and Concerns of Hearing Loss on Social Q&A Sites: Incorporating Patients' Perspective

Hearing loss is the most common human sensory deficit, affecting normal communication. Recently, patients with hearing loss or at risk of hearing loss are increasingly turning to the online health community for health information and support. Information on health-related topics exchanged on the Internet is a useful resource to examine patients' informational needs. The ability to understand the patients' perspectives on hearing loss is critical for health professionals to develop a patient-centered intervention. In this paper, we apply Latent Dirichlet Allocation (LDA) on electronic patient-authored questions on social question-and-answer (Q&A) sites to identify patients' perceptions, concerns, and needs on hearing loss. Our results reveal 21 topics, which are both representative and meaningful, and mostly correspond to sub-fields established in hearing science research. The latent topics are classified into five themes, which include "sudden hearing loss", "tinnitus", "noise-induced hearing loss", "hearing aids", "dizziness", "curiosity about hearing loss", "otitis media" and "complications of disease". Our topic analysis of patients' questions on the topic of hearing loss allows achieving a thorough understanding of patients' perspectives, thereby leading to better development of the patient-centered intervention.

Relationship Between Domain-Specific Cognitive Function and Speech-in-Noise Performance in Older Adults: The Atherosclerosis Risk in Communities Hearing Pilot Study

Purpose The purpose of this study was to investigate associations between performance on a clinical speech-in-noise measure with a comprehensive neurocognitive battery of tests. Method A group of older adults (N = 250, M _age = 77 years, age range: 67.3-89.1 years) enrolled in the Atherosclerosis Risk in Communities Neurocognitive Study took part in the hearing pilot study (2013) that included testing for audiometric thresholds and speech-in-noise performance (Quick Speech-in-Noise Test; Killion, Niquette, Gudmundsen, Revit, & Banerjee, 2004). This research study analyzed the associations between domain-specific cognitive function and speech-in-noise performance after adjusting for hearing thresholds and other demographic and cardiovascular factors. Results Multivariable-adjusted associations were found between all cognitive domains and speech-in-noise performance in the full sample, but the observed associations varied when participants with varying levels of moderate to moderately severe hearing loss were excluded from the analysis. Conclusions The findings are discussed in terms considering the cognitive status of older adults in relation to their speech-in-noise performance during audiological evaluation and implications for aural rehabilitation.

Effects of Phase-Locking Deficits on Speech Recognition in Older Adults With Presbycusis

Objective: People with presbycusis (PC) often report difficulties in speech recognition, especially under noisy listening conditions. Investigating the PC-related changes in central representations of envelope signals and temporal fine structure (TFS) signals of speech sounds is critical for understanding the mechanism underlying the PC-related deficit in speech recognition. Frequency-following responses (FFRs) to speech stimulation can be used to examine the subcortical encoding of both envelope and TFS speech signals. This study compared FFRs to speech signals between listeners with PC and those with clinically normal hearing (NH) under either quiet or noise-masking conditions.

Methods: FFRs to a 170-ms speech syllable /da/ were recorded under either a quiet or noise-masking (with a signal-to-noise ratio (SNR) of 8 dB) condition in 14 older adults with PC and 13 age-matched adults with NH. The envelope (FFR_ENV) and TFS (FFR_TFS) components of FFRs were analyzed separately by adding and subtracting the alternative polarity responses, respectively. Speech recognition in noise was evaluated in each participant.

Results: In the quiet condition, compared with the NH group, the PC group exhibited smaller F0 and H3 amplitudes and decreased stimulus-response (S-R) correlation for FFR_ENV but not for FFR_TFS. Both the H2 and H3 amplitudes and the S-R correlation of FFR_ENV significantly decreased in the noise condition compared with the quiet condition in the NH group but not in the PC group. Moreover, the degree of hearing loss was correlated with noise-induced changes in FFR_TFS morphology. Furthermore, the speech-in-noise (SIN) threshold was negatively correlated with the noise-induced change in H2 (for FFR_ENV) and the S-R correlation for FFR_ENV in the quiet condition.

Conclusion: Audibility affects the subcortical encoding of both envelope and TFS in PC patients. The impaired ability to adjust the balance between the envelope and TFS in the noise condition may be part of the mechanism underlying PC-related deficits in speech recognition in noise. FFRs can predict SIN perception performance.

Effect of improving audibility on better-ear glimpsing using non-linear amplification

Better-ear glimpsing (BEG) utilizes interaural level differences (ILDs) to improve speech intelligibility in noise. This spatial benefit is reduced in most hearing-impaired (HI) listeners due to their increased hearing loss at high frequencies. Even though this benefit can be improved by providing increased amplification, the improvement is limited by loudness discomfort. An alternative solution therefore extends ILDs to low frequencies, which has been shown to provide a substantial benefit from BEG. In contrast to previous studies, which only applied linear stimulus manipulations, wide dynamic range compression was applied here to improve the audibility of soft sounds while ensuring loudness comfort for loud sounds. Performance in both speech intelligibility and BEG was measured in 13 HI listeners at three different masker levels and for different interaural stimulus manipulations. The results revealed that at low signal levels, performance substantially improved with increasing masker level, but this improvement was reduced by the compressive behaviour at higher levels. Moreover, artificially extending ILDs by applying infinite (broadband) ILDs provided an extra spatial benefit in speech reception thresholds of up to 5 dB on top of that already provided by natural ILDs and interaural time differences, which increased with increasing signal level.

Clear speech adaptations in spontaneous speech produced by young and older adults

The study investigated the speech adaptations by older adults (OA) with and without age-related hearing loss made to communicate effectively in challenging communicative conditions. Acoustic analyses were carried out on spontaneous speech produced during a problem-solving task (diapix) carried out by talker pairs in different listening conditions. There were 83 talkers of Southern British English. Fifty-seven talkers were OAs aged 65-84, 30 older adults with normal hearing (OANH), and 27 older adults with hearing loss (OAHL) [mean pure tone average (PTA) 0.250-4 kHz: 27.7 dB HL]. Twenty-six talkers were younger adults (YA) aged 18-26 with normal hearing. Participants were recorded while completing the diapix task with a conversational partner (YA of the same sex) when (a) both talkers heard normally (NORM), (b) the partner had a simulated hearing loss, and (c) both talkers heard babble noise. Irrespective of hearing status, there were age-related differences in some acoustic characteristics of YA and OA speech produced in NORM, most likely linked to physiological factors. In challenging conditions, while OANH talkers typically patterned with YA talkers, OAHL talkers made adaptations more consistent with an increase in vocal effort. The study suggests that even mild presbycusis in healthy OAs can affect the speech adaptations made to maintain effective communication.

Effects of Binaural Spatialization in Wireless Microphone Systems for Hearing Aids on Normal-Hearing and Hearing-Impaired Listeners

Little is known about the perception of artificial spatial hearing by hearing-impaired subjects. The purpose of this study was to investigate how listeners with hearing disorders perceived the effect of a spatialization feature designed for wireless microphone systems. Forty listeners took part in the experiments. They were arranged in four groups: normal-hearing, moderate, severe, and profound hearing loss. Their performance in terms of speech understanding and speaker localization was assessed with diotic and binaural stimuli. The results of the speech intelligibility experiment revealed that the subjects presenting a moderate or severe hearing impairment better understood speech with the spatialization feature. Thus, it was demonstrated that the conventional diotic binaural summation operated by current wireless systems can be transformed to reproduce the spatial cues required to localize the speaker, without any loss of intelligibility. The speaker localization experiment showed that a majority of the hearing-impaired listeners had similar performance with natural and artificial spatial hearing, contrary to the normal-hearing listeners. This suggests that certain subjects with hearing impairment preserve their localization abilities with approximated generic head-related transfer functions in the frontal horizontal plane.

Age-related changes in auditory processing and speech perception: cross-sectional and longitudinal analyses

Age-related differences in speech perception have been shown in previous cross-sectional studies to be related to auditory temporal processing. We examined this association in both cross-sectional and longitudinal designs, controlling for age-related changes in hearing sensitivity and cognitive ability. Fifty-eight participants were tested in two phases. In phase 1, ages ranged between 22 and 82 years. Phase 2 occurred seven years later. In both phases, participants performed auditory processing tasks, speech perception tests, and cognitive tasks. In both phases, age correlated with hearing level, auditory temporal processing thresholds, word recognition accuracy in noise, and compressed speech. Auditory temporal processing thresholds were correlated with word recognition accuracy in narrowband noise and compressed speech. Longitudinal analysis showed significant decreases in performance from phase 1 to phase 2 in hearing level, dichotic TOJ thresholds, and word recognition accuracy. Steeper slopes were observed in phase 2 than in phase 1 for correlations between age, hearing level, and word recognition accuracy in narrowband noise, but not for age and dichotic TOJ thresholds. Generalized estimating equations revealed an overall decrease in word recognition accuracy from phase 1 to phase 2; this decrease was larger for older participants. Increases in dichotic TOJ and gap detection thresholds were associated with a decrease over time in speech in narrowband and broadband noise, and compressed speech, even when adjusted for age, hearing level, and cognitive ability. These results show that both cross-sectional and longitudinal designs yield similar significant associations between temporal processing and speech perception, even when adjusted for hearing level and cognitive ability.

The effect of tone-vocoding on spatial release from masking for old, hearing-impaired listeners

Old, hearing-impaired listeners generally benefit little from lateral separation of multiple talkers when listening to one of them. This study aimed to determine how spatial release from masking (SRM) in such listeners is affected when the interaural time differences (ITDs) in the temporal fine structure (TFS) are manipulated by tone-vocoding (TVC) at the ears by a master hearing aid system. Word recall was compared, with and without TVC, when target and masker sentences from a closed set were played simultaneously from the front loudspeaker (co-located) and when the maskers were played 45° to the left and right of the listener (separated). For 20 hearing-impaired listeners aged 64 to 86, SRM was 3.7 dB smaller with TVC than without TVC. This difference in SRM correlated with mean audiometric thresholds below 1.5 kHz, even when monaural TFS sensitivity (discrimination of frequency-shifts in identically filtered complexes) was partialed out, suggesting that low-frequency audiometric thresholds may be a good indicator of candidacy for hearing aids that preserve ITDs. The TVC difference in SRM was not correlated with age, pure-tone ITD thresholds, nor fundamental frequency difference limens, and only with monaural TFS sensitivity before control for low-frequency audiometric thresholds.

Intra- and Intersubject Variability in Audiometric Measures and Loudness Judgments in Older Listeners with Normal Hearing

This research was to document intra- and intersubject variability in measures of pure tone thresholds, loudness discomfort levels, and the Contour test of loudness for tonal and speech stimuli across 8 to 10 repeated test sessions over a period of almost 1 year in a group of 11 normal-hearing, older middle-aged adults (39 to 73 years, mean of 56 years). The measured pure tone thresholds and loudness discomfort levels were determined to be stable across sessions, with variability on the order of 5 dB. The categorical judgments for the Contour test for both warbled tones and spondaic speech stimuli decreased over time in level required for categories greater than comfortable. This result contrasts with reports of a slight increase over time when young, normal-hearing adults were tested in comparable measures. The intrasubject variability in the Contour test results was greatest for the 4,000-Hz tonal stimulus for which the largest time effects were observed. The intersubject variability was typically greater than the intrasubject variability and typically increased as the loudness category increased, with some exceptions. The results from this study can be used to aid in power and sample size analyses using these measures in future studies designed to compare effects of treatments based on changes in loudness judgments over time.

Coding deficits in hidden hearing loss induced by noise: the nature and impacts

Hidden hearing refers to the functional deficits in hearing without deterioration in hearing sensitivity. This concept is proposed based upon recent finding of massive noise-induced damage on ribbon synapse between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) in the cochlea without significant permanent threshold shifts (PTS). Presumably, such damage may cause coding deficits in auditory nerve fibers (ANFs). However, such deficits had not been detailed except that a selective loss of ANFs with low spontaneous rate (SR) was reported. In the present study, we investigated the dynamic changes of ribbon synapses and the coding function of ANF single units in one month after a brief noise exposure that caused a massive damage of ribbon synapses but no PTS. The synapse count and functional response measures indicates a large portion of the disrupted synapses were re-connected. This is consistent with the fact that the change of SR distribution due to the initial loss of low SR units is recovered quickly. However, ANF coding deficits were developed later with the re-establishment of the synapses. The deficits were found in both intensity and temporal processing, revealing the nature of synaptopathy in hidden hearing loss.

Effect of exercise on the auditory discrimination task in perimenopausal women: a preliminary study

Background The climacteric phase of menopausal transition (perimenopause) is marked by reproductive hormone fluctuations and reduced cognitive capacity. Exercise enhances neurocognitive performance. However, auditory perceptual sensitivity has not been examined. Purpose This study aimed to determine the effect of aerobic exercise on the response speed (reaction time) and error rate during auditory processing among perimenopausal women. Methods Three pitches (500, 1000, and 2000 Hz) were used during a simple auditory discrimination task, which was performed before and after exercise. We included 14 perimenopausal women and 17 right-handed young women (aged 46-54 years and 18-22 years, respectively). To achieve similar exercise intensity in both groups, we proposed two types of physical activities for each group. Mixed models statistics were used to analyze the reaction time and error rate before and after training in the two groups. Results Perimenopausal women exhibited a significantly longer reaction time than young women during the baseline auditory discrimination task (p < 0.05) but not during the second test. The error rate decreased significantly after exercise among perimenopausal women (p < 0.05) but not among young women. Thus, exercise had a stronger beneficial influence on auditory plasticity or sensitivity for perimenopausal women than for young women. Conclusion The ability of aerobic exercise to modulate auditory neurocognitive performance differs between the two groups. Aerobic exercise improves auditory discrimination performance specifically for perimenopausal women. These results provide preliminary evidence concerning the acoustic features of middle-aged women, underscoring the importance of exercise for preventing decline in auditory cognitive function in perimenopausal women.

The Effects of Linguistic Context on Word Recognition in Noise by Elderly Listeners Using Spanish Sentence Lists (SSL)

This study evaluated the effects of the linguistic context on the recognition of words in noise in older listeners using the Spanish Sentence Lists. These sentences were developed based on the approach of the SPIN test for the English language, which contains high and low predictability (HP and LP) sentences. In addition, the relative contribution of peripheral hearing sensitivity, measured by pure-tone hearing thresholds (PTA), to the performance on both types of sentences was assessed in a regression analysis. The results showed that older listeners obtained benefits on word recognition from the linguistic context. PTA contributed significantly to explaining the variance in performance on both HP and LP sentences.

Effect of audibility on spatial release from speech-on-speech masking

This study investigated to what extent spatial release from masking (SRM) deficits in hearing-impaired adults may be related to reduced audibility of the test stimuli. Sixteen adults with sensorineural hearing loss and 28 adults with normal hearing were assessed on the Listening in Spatialized Noise-Sentences test, which measures SRM using a symmetric speech-on-speech masking task. Stimuli for the hearing-impaired listeners were delivered using three amplification levels (National Acoustic Laboratories - Revised Profound prescription (NAL-RP) +25%, and NAL-RP +50%), while stimuli for the normal-hearing group were filtered to achieve matched audibility. SRM increased as audibility increased for all participants. Thus, it is concluded that reduced audibility of stimuli may be a significant factor in hearing-impaired adults' reduced SRM even when hearing loss is compensated for with linear gain. However, the SRM achieved by the normal hearers with simulated audibility loss was still significantly greater than that achieved by hearing-impaired listeners, suggesting other factors besides audibility may still play a role.

Hearing Aid-Induced Plasticity in the Auditory System of Older Adults: Evidence From Speech Perception

PURPOSE

We tested whether using hearing aids can improve unaided performance in speech perception tasks in older adults with hearing impairment.

METHOD

Unaided performance was evaluated in dichotic listening and speech-in-noise tests in 47 older adults with hearing impairment; 36 participants in 3 study groups were tested before hearing aid fitting and after 4, 8, and 14 weeks of hearing-aid use. The remaining 11 participants served as a control group and were similarly evaluated but were not fitted with hearing aids. Three protocols were compared in the study groups: amplification for the nondominant ear, amplification for the dominant ear, and bilateral amplification. Subsequently, after 4 weeks, all participants were afforded bilateral amplification.

RESULTS

In the study groups, unaided dichotic listening scores improved significantly in the nondominant ear by 8 weeks and onward. Significant improvements were also observed for unaided speech identification in noise, with some gains apparent after 4 weeks of hearing-aid use. No gains were observed in the control group.

CONCLUSIONS

Using hearing aids for a relatively short period can induce changes in the way older adults process auditory inputs in perceptual tasks such as speech identification in noise and dichotic listening. These changes suggest that the central auditory system of older adults retains the potential for behaviorally relevant plasticity.

Age-related changes in sound localisation ability

Auditory spatial processing is an important ability in everyday life and allows the processing of omnidirectional information. In this review, we report and compare data from psychoacoustic and electrophysiological experiments on sound localisation accuracy and auditory spatial discrimination in infants, children, and young and older adults. The ability to process auditory spatial information changes over lifetime: the perception of the acoustic space develops from an initially imprecise representation in infants and young children to a concise representation of spatial positions in young adults and the respective performance declines again in older adults. Localisation accuracy shows a strong deterioration in older adults, presumably due to declined processing of binaural temporal and monaural spectro-temporal cues. When compared to young adults, the thresholds for spatial discrimination were strongly elevated both in young children and older adults. Despite the consistency of the measured values the underlying causes for the impaired performance might be different: (1) the effect is due to reduced cognitive processing ability and is thus task-related; (2) the effect is due to reduced information about the auditory space and caused by declined processing in auditory brain stem circuits; and (3) the auditory space processing regime in young children is still undergoing developmental changes and the interrelation with spatial visual processing is not yet established. In conclusion, we argue that for studying auditory space processing over the life course, it is beneficial to investigate spatial discrimination ability instead of localisation accuracy because it more reliably indicates changes in the processing ability.

Speech recognition across the lifespan: Longitudinal changes from middle age to older adults

Purpose

To provide an overview of evidence of age-related declines in speech recognition in middle-age to older adults, review contributions of pure-tone thresholds, age, and gender, and report preliminary results from a longitudinal study.

Methods

Pure-tone thresholds and word recognition in quiet and babble are being measured in a large sample of adults yearly or every 2-3 years. Analyses included >1,200 adults whose ages ranged from 40s to 90s, with >16,000 audiograms and speech recognition scores. A multivariable generalized linear repeated mixed model assessed changes in thresholds and speech recognition over time.

Results

Word recognition in quiet declined significantly while controlling for threshold increases, and declines appeared to accelerate near age 65-70. Scores for males were poorer than for females even after controlling for gender differences in thresholds, but rates of decline did not differ by gender. Smaller declines in key word recognition in babble were observed and declines appeared to accelerate near age 75-80.

Conclusions

Additional evidence is needed from large-scale longitudinal cohort studies to determine rates of change of auditory function across the lifespan. These studies can identify associations with modifiable risk factors and potential mechanisms to reduce, prevent, or delay the onset of age-related hearing loss.

Effects of ageing and hearing thresholds on speech perception in quiet and in noise perceived in different locations

Background and Objectives

This study investigated the effect of ageing on speech perception in quiet and in noise, with noise directed from front, right and left.

Subjects and Methods

Sixty Malay native adults with normal or near normal hearing comprising of 20 young adults (21 to 39 years old), 20 middle aged (40 to 59 years old) and 20 older adults (60 to 74 years old) participated in this study. Their speech perception ability was measured using the Malay Hearing in Noise Test (HINT) in four test conditions; 1) in quiet (HINT Q), 2) with noise from front (HINT NF), 3) with noise from right (HINT NR), and 4) with noise from left (HINT NL). Reception thresholds for sentences (RTSs) were measured in each of the aforementioned conditions using an adaptive method.

Results

The results showed that, 1) genuine age-related decline was found in speech perception performance in HINT (NF), 2) hearing threshold was a major determinant differentiating speech perception performance for HINT (Q) and HINT (NL) conditions, and 3) speech perception performance for HINT (NR) was determined by both age and hearing threshold.

Conclusions

This study suggests that, in older adults, while hearing thresholds affect speech perception in quiet, other factors such as central auditory processing and cognitive functions might be more important determinant factors for speech perception performance in noise.

Greater BOLD variability in older compared with younger adults during audiovisual speech perception

Older adults exhibit decreased performance and increased trial-to-trial variability on a range of cognitive tasks, including speech perception. We used blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) to search for neural correlates of these behavioral phenomena. We compared brain responses to simple speech stimuli (audiovisual syllables) in 24 healthy older adults (53 to 70 years old) and 14 younger adults (23 to 39 years old) using two independent analysis strategies: region-of-interest (ROI) and voxel-wise whole-brain analysis. While mean response amplitudes were moderately greater in younger adults, older adults had much greater within-subject variability. The greatly increased variability in older adults was observed for both individual voxels in the whole-brain analysis and for ROIs in the left superior temporal sulcus, the left auditory cortex, and the left visual cortex. Increased variability in older adults could not be attributed to differences in head movements between the groups. Increased neural variability may be related to the performance declines and increased behavioral variability that occur with aging.

How difficult is difficult? Speech perception in noise in the elderly hearing impaired

BACKGROUND

Perception of speech in the presence of competing multitalker noise is difficult for most individuals with sensory hearing loss, and in particular, for the elderly hearing impaired. Elderly people frequently report that these difficulties are poorly compensated for by hearing aids, albeit the algorithms and technologies aiming to improve speech perception in noise. The aim of the current study was therefore to assess competing speech signals processing by measuring the amount of signal to noise ratio (SNR) loss experienced by elderly hearing impaired individuals and their performance in dichotic listening tests.

METHODS

Speech in multitalker babble noise and dichotic listening were assessed in older hearing impaired individuals and in young normal-hearing adults.

RESULTS

The average dichotic scores in the elderly group were substantially and significantly lower compared with the scores of the younger group with a significant right ear advantage (higher accuracy in reporting words arriving at the right ear than words arriving at the left ear) in the elderly group. Speech identification in noise in the older group was significantly poorer than in the younger group (SNR loss: 10 dB).

CONCLUSIONS

The poor performance in the elderly hearing impaired group highlights the difficulties faced by hearing impaired older adults in demanding listening environments. Our results suggest that it may be unreasonable to expect that elderly hearing impaired individuals may fully understand speech in multitalker environments even when hearing aids are used.

Spatial separation benefit for unaided and aided listening

OBJECTIVES

The benefit attributable to spatial separation of speech and noise was measured as a function of low-pass cutoff frequency with and without bilateral hearing aids.

DESIGN

Fourteen younger and 10 older adults with normal hearing and 12 older adults with mild-to-moderate sloping high frequency hearing loss were included to assess the effects of age and hearing loss. Subjects with hearing loss were provided commercially available bilateral hearing aids. Consonant recognition was measured at 70 dB SPL in a background of speech-shaped noise at 66 dB SPL. Speech and noise were low-pass filtered at 1.7, 3.4, and 7.1 kHz. Nonsense syllables were always at 0° and noise was at either 0° or 90°. Speech and noise spectra for all conditions were digitally recorded using a probe microphone placed in each ear canal of each subject. Spectra and levels of speech, and quiet thresholds for narrowband noises, were used to calculate the Articulation Index and provide predictions of unaided and aided (hearing-impaired only) consonant recognition, spatial benefit, and hearing aid benefit for each condition. Subjective ratings of workload (NASA Task Load Index) were obtained for all unaided and aided measures of speech recognition.

RESULTS

Consonant recognition in noise improved for all groups with speech and noise spatially separated and with the addition of high-frequency speech information. Scores were poorer overall for the older adults with hearing loss than for the other groups. For normal-hearing subjects, observed scores and spatial benefit were better than predicted. For hearing-impaired subjects, scores did not significantly improve with hearing aids, even with higher frequencies and spatial separation, and were poorer than predicted especially for aided listening. Similar to subjects with normal hearing, spatial benefit for hearing-impaired subjects was larger than predicted.

CONCLUSIONS

Younger and older adults with normal hearing benefited from spatial separation of speech and noise sources to a greater extent than predicted based on simple audibility. Thus, no age-related deficits in the use of interaural difference cues were observed. Although hearing aid benefit was negligible, perceived listening effort was lower aided than unaided, especially with spatial separation. Articulation Index predictions revealed that speech audibility was generally restored with hearing aids across a wide bandwidth of speech, especially in the far ear. Thus, reduced audibility was not a primary factor in limited hearing aid benefit, suggesting that peripheral, central-auditory and/or cognitive changes may have played a role. In contrast, unaided and aided spatial benefit was better than predicted, and spatial benefit was slightly larger with hearing aids than without. Thus, these older adults with hearing loss using bilateral hearing aids were able to take advantage of binaural cues to improve consonant recognition in noise.

Hearing loss in older critical care patients: participation in decision making

Older adults with hearing loss who receive care in the noisy environment of a critical care unit can be disadvantaged in their ability to understand speech, thus limiting their participation in decision making. Providing optimal outcomes for such patients can be understood through use of the American Association of Critical-Care Nurses Synergy Model. When older adults are admitted to a critical care unit, their spouses, children, and friends are in positions to participate in the patients' care. The AACN Synergy Model patient characteristic of participation in care is useful in enhancing optimal outcomes for older patients.

Working memory, age, and hearing loss: susceptibility to hearing aid distortion

OBJECTIVES

Hearing aids use complex processing intended to improve speech recognition. Although many listeners benefit from such processing, it can also introduce distortion that offsets or cancels intended benefits for some individuals. The purpose of the present study was to determine the effects of cognitive ability (working memory) on individual listeners' responses to distortion caused by frequency compression applied to noisy speech.

DESIGN

The present study analyzed a large data set of intelligibility scores for frequency-compressed speech presented in quiet and at a range of signal-to-babble ratios. The intelligibility data set was based on scores from 26 adults with hearing loss with ages ranging from 62 to 92 years. The listeners were grouped based on working memory ability. The amount of signal modification (distortion) caused by frequency compression and noise was measured using a sound quality metric. Analysis of variance and hierarchical linear modeling were used to identify meaningful differences between subject groups as a function of signal distortion caused by frequency compression and noise.

RESULTS

Working memory was a significant factor in listeners' intelligibility of sentences presented in babble noise and processed with frequency compression based on sinusoidal modeling. At maximum signal modification (caused by both frequency compression and babble noise), the factor of working memory (when controlling for age and hearing loss) accounted for 29.3% of the variance in intelligibility scores. Combining working memory, age, and hearing loss accounted for a total of 47.5% of the variability in intelligibility scores. Furthermore, as the total amount of signal distortion increased, listeners with higher working memory performed better on the intelligibility task than listeners with lower working memory did.

CONCLUSIONS

Working memory is a significant factor in listeners' responses to total signal distortion caused by cumulative effects of babble noise and frequency compression implemented with sinusoidal modeling. These results, together with other studies focused on wide-dynamic range compression, suggest that older listeners with hearing loss and poor working memory are more susceptible to distortions caused by at least some types of hearing aid signal-processing algorithms and by noise, and that this increased susceptibility should be considered in the hearing aid fitting process.

Effects of ageing on speed and temporal resolution of speech stimuli in older adults

BACKGROUND

According to previous studies, most of the speech recognition disorders in older adults are theresults of deficits in audibility and auditory temporal resolution. In this paper, the effect of ageing on timecompressedspeech and auditory temporal resolution by word recognition in continuous and interrupted noisewas studied.

METHODS

A time-compressed speech test (TCST) was conducted on 30 young and 32 older adults with normalhearing thresholds. Lists of monosyllabic words were used at three time compression ratios. Auditory temporalresolution was determined by measuring the monosyllabic word recognition score (WRS), in the presence ofcontinuous and interrupted noise, at three signal-to-noise ratios (S/Ns).

RESULTS

There was a significant difference in TCST scores at the three compression ratios within and betweenyoung and older adult none (p< 0.001). Similar results were obtained in WRSs at the three S/Ns in the presenceof interrupted and continuous noise (p< 0.001), and in the degree of auditory temporal resolution(p=0.007). A significant correlation was found between the level of test difficulty of TCST with WRSs in bothyoung (r = 0.549, P=0.002) and older adults (r= 0.531, P=0.003).

CONCLUSION

Our results showed that ageing remarkably affects the processing of fast speech stimuli and temporalresolving ability. These results are more supportive of the effect of ageing on speech perception than onloss of hearing.

The influence of environmental sound training on the perception of spectrally degraded speech and environmental sounds

Perceptual training with spectrally degraded environmental sounds results in improved environmental sound identification, with benefits shown to extend to untrained speech perception as well. The present study extended those findings to examine longer-term training effects as well as effects of mere repeated exposure to sounds over time. Participants received two pretests (1 week apart) prior to a week-long environmental sound training regimen, which was followed by two posttest sessions, separated by another week without training. Spectrally degraded stimuli, processed with a four-channel vocoder, consisted of a 160-item environmental sound test, word and sentence tests, and a battery of basic auditory abilities and cognitive tests. Results indicated significant improvements in all speech and environmental sound scores between the initial pretest and the last posttest with performance increments following both exposure and training. For environmental sounds (the stimulus class that was trained), the magnitude of positive change that accompanied training was much greater than that due to exposure alone, with improvement for untrained sounds roughly comparable to the speech benefit from exposure. Additional tests of auditory and cognitive abilities showed that speech and environmental sound performance were differentially correlated with tests of spectral and temporal-fine-structure processing, whereas working memory and executive function were correlated with speech, but not environmental sound perception. These findings indicate generalizability of environmental sound training and provide a basis for implementing environmental sound training programs for cochlear implant (CI) patients.

Word recognition within a linguistic context: effects of age, hearing acuity, verbal ability, and cognitive function

OBJECTIVE

Participants in traditional studies of the effects of context on spoken word recognition have been university undergraduates. When older adults have been included, they have typically been matched with these young adults for verbal ability or years of education. Although this may be a good strategy for eliminating confounding variables, it is not clear how results of these studies may extend to the general population of young and older adults. The objective of this study was to examine the effects of adult age, hearing acuity, verbal ability, and cognitive function on the use of linguistic context in spoken word recognition.

DESIGN

Fifty-three adults, aged 19 to 89 yr, heard short sentences in which the final word was masked by multitalker babble. The level of babble was progressively reduced in 2 dB steps until the sentence-final word could be correctly identified. Published norms were used to construct sets of sentences in which the same word could be heard with three levels of predictability (low, medium, and high) based on the linguistic context. In a fourth condition (no context), the words were preceded by a neutral carrier phrase. Participants received tests of verbal ability, with an emphasis on vocabulary knowledge, a brief test battery to assess cognitive function, and an assessment of hearing acuity based on pure-tone thresholds. Participants' hearing acuity ranged from normal acuity to moderate hearing loss.

RESULTS

Results showed that the signal to noise ratio necessary for correct word recognition varied inversely with the probability of that word occurring in the sentence context. Hearing loss had a significant effect on word recognition for words heard in a neutral context, but the effect of hearing acuity diminished progressively with increasing contextual probability of the target word. Hierarchical multiple regressions showed that hearing acuity accounted for a significant amount of the variance at the lowest three levels of contextual probability but not at the highest probability level tested. Cognitive function contributed significantly to the obtained variance in word recognition performance at all levels of contextual probability tested. Moreover, participant age accounted for a significant amount of variance even after hearing acuity and cognitive function were taken into account. Verbal ability in the range represented by the test participants did not contribute significantly to recognition performance in any of the context conditions.

CONCLUSIONS

Peripheral hearing acuity accounted for only a part of the variance in word recognition accuracy, with significant variance also contributed by individual differences in cognitive function and participant age. Results showed the ability to use linguistic context to aid spoken word recognition is sufficiently robust that a relatively wide range in verbal ability among native English speakers had no effect on recognition performance.

Problems hearing in noise in older adults: a review of spatial processing disorder

Difficulty understanding speech in background noise, even with amplification to restore audibility, is a common problem for hearing-impaired individuals and is especially frequent in older adults. Despite the debilitating nature of the problem the cause is not yet completely clear. This review considers the role of spatial processing ability in understanding speech in noise, highlights the potential impact of disordered spatial processing, and attempts to establish if aging leads to reduced spatial processing ability. Evidence supporting and opposing the hypothesis that spatial processing is disordered among the aging population is presented. With a few notable exceptions, spatial processing ability was shown to be reduced in an older population in comparison to young adults, leading to poorer speech understanding in noise. However, it is argued that to conclude aging negatively effects spatial processing ability may be oversimplified or even premature given potentially confounding factors such as cognitive ability and hearing impairment. Further research is required to determine the effect of aging and hearing impairment on spatial processing and to investigate possible remediation options for spatial processing disorder.