Attenuation and distortion components of age-related hearing loss: Contributions to recognizing temporal-envelope filtered speech in modulated noise.

Older adults with hearing loss may experience difficulty recognizing speech in noise due to factors related to attenuation (e.g., reduced audibility and sensation levels, SLs) and distortion (e.g., reduced temporal fine structure, TFS, processing). Furthermore, speech recognition may improve when the amplitude modulation spectrum of the speech and masker are non-overlapping. The current study investigated this by filtering the amplitude modulation spectrum into different modulation rates for speech and speech-modulated noise. The modulation depth of the noise was manipulated to vary the SL of speech glimpses. Younger adults with normal hearing and older adults with normal or impaired hearing listened to natural speech or speech vocoded to degrade TFS cues. Control groups of younger adults were tested on all conditions with spectrally shaped speech and threshold matching noise, which reduced audibility to match that of the older hearing-impaired group. All groups benefitted from increased masker modulation depth and preservation of syllabic-rate speech modulations. Older adults with hearing loss had reduced speech recognition across all conditions. This was explained by factors related to attenuation, due to reduced SLs, and distortion, due to reduced TFS processing, which resulted in poorer auditory processing of speech cues during the dips of the masker.

Relationship between Memory Load and Listening Demands in Age-Related Hearing Impairment.

Age-related hearing loss has been associated with increased recruitment of frontal brain areas during speech perception to compensate for the decline in auditory input. This additional recruitment may bind resources otherwise needed for understanding speech. However, it is unknown how increased demands on listening interact with increasing cognitive demands when processing speech in age-related hearing loss. The current study used a full-sentence working memory task manipulating demands on working memory and listening and studied untreated mild to moderate hard of hearing (n = 20) and normal-hearing age-matched participants (n = 19) with functional MRI. On the behavioral level, we found a significant interaction of memory load and listening condition; this was, however, similar for both groups. Under low, but not high memory load, listening condition significantly influenced task performance. Similarly, under easy but not difficult listening conditions, memory load had a significant effect on task performance. On the neural level, as measured by the BOLD response, we found increased responses under high compared to low memory load conditions in the left supramarginal gyrus, left middle frontal gyrus, and left supplementary motor cortex regardless of hearing ability. Furthermore, we found increased responses in the bilateral superior temporal gyri under easy compared to difficult listening conditions. We found no group differences nor interactions of group with memory load or listening condition. This suggests that memory load and listening condition interacted on a behavioral level, however, only the increased memory load was reflected in increased BOLD responses in frontal and parietal brain regions. Hence, when evaluating listening abilities in elderly participants, memory load should be considered as it might interfere with the assessed performance. We could not find any further evidence that BOLD responses for the different memory and listening conditions are affected by mild to moderate age-related hearing loss.

The World Health Organization's hearing-impairment grading system: an evaluation for unaided communication in age-related hearing loss.

OBJECTIVE: This review evaluated the data from five datasets having pure-tone thresholds and functional measures of speech communication from relatively large groups of older adults to evaluate the validity of the proposed new World Health Organisation (WHO) hearing-impairment grading system, referred to here as WHO-proposed. DESIGN: This was a review of studies identified from the literature having both pure-tone audiometry and functional measures of speech communication from relatively large samples of older adults. STUDY SAMPLE: Three population or population-sample datasets and two clinical datasets were identified with access provided to de-identified data for five of these six studies. RESULTS: As the WHO-proposed hearing-impairment grade progressed from "normal" to "severe" (insufficient data from older adults were available for the "profound" category), each step in this progression led to a significant difference in functional communication relative to the preceding step. Cohen's d effect sizes were moderate to very large between each successive step on the WHO-proposed hearing-impairment grading scale, with some exceptions for the step from "normal" to "mild/slight" grades. CONCLUSIONS: The WHO-proposed hearing-impairment grading system, recently developed through expert opinion and adopted by WHO, is validated here with evidence from studies of functional communication in older adults.

Speech understanding in noise in elderly adults: the effect of inhibitory control and syntactic complexity.

BACKGROUND: Previous research has suggested that speech perception in elderly adults is influenced not only by age-related hearing loss or presbycusis but also by declines in cognitive abilities, by background noise and by the syntactic complexity of the message. AIMS: To gain further insight into the influence of these cognitive as well as acoustic and linguistic factors on speech perception in elderly adults by investigating inhibitory control as a listener characteristic and background noise type and syntactic complexity as input characteristics. METHODS & PROCEDURES: Phoneme identification was measured in different noise conditions and in different linguistic contexts (single words, sentences with varying syntactic complexity). Additionally, inhibitory control was measured using a visual stimulus-response matching task. Fifty-one adults participated in this study, including elderly adults with age-related hearing loss (n = 9) and with normal hearing (n = 17), and a control group of normal hearing younger adults (n = 25). OUTCOMES & RESULTS: The analysis revealed that elderly adults with normal hearing and with hearing loss were less likely to identify successfully phonemes in single words than younger normal hearing controls. In the context of sentences, only elderly adults with hearing loss had a lower odds of correct phoneme perception than the control group. Additionally, in elderly adults with hearing loss, phoneme-in-sentence perception was linked to age-related declines in inhibitory control. In all participants, phoneme identification in sentences was influenced by both noise type and syntactic complexity. CONCLUSIONS & IMPLICATIONS: Inhibitory control and syntactic complexity might play a significant role in speech perception, especially in elderly listeners. These factors might also influence the results of clinical assessments of speech perception. Testing procedures thus need to be selected and their results interpreted carefully with these influences in mind.

Extension and evaluation of a near-end listening enhancement algorithm for listeners with normal and impaired hearing.

In many applications in which speech is played back via a sound reinforcement system such as public address systems and mobile phones, speech intelligibility is degraded by additive environmental noise. A possible solution to maintain high intelligibility in noise is to pre-process the speech signal based on the estimated noise power at the position of the listener. The previously proposed AdaptDRC algorithm [Schepker, Rennies, and Doclo (2015). J. Acoust. Soc. Am. 138, 2692-2706] applies both frequency shaping and dynamic range compression under an equal-power constraint, where the processing is adaptively controlled by short-term estimates of the speech intelligibility index. Previous evaluations of the algorithm have focused on normal-hearing listeners. In this study, the algorithm was extended with an adaptive gain stage under an equal-peak-power constraint, and evaluated with eleven normal-hearing and ten mildly to moderately hearing-impaired listeners. For normal-hearing listeners, average improvements in speech reception thresholds of about 4 and 8 dB compared to the unprocessed reference condition were measured for the original algorithm and its extension, respectively. For hearing-impaired listeners, the average improvements were about 2 and 6 dB, indicating that the relative improvement due to the proposed adaptive gain stage was larger for these listeners than the benefit of the original processing stages.

Speech based transmission index for all: An intelligibility metric for variable hearing ability.

A method to measure the speech intelligibility in public address systems for normal hearing and hearing impaired persons is presented. The proposed metric is an extension of the speech based Speech Transmission Index to account for accurate perceptual masking and variable hearing ability: The sound excitation pattern generated at the ear is accurately computed using an auditory filter model, and its shapes depend on frequency, sound level, and hearing impairment. This extension yields a better prediction of the intensity of auditory masking which is used to rectify the modulation transfer function and thus to objectively assess the speech intelligibility experienced by hearing impaired as well as by normal hearing persons in public spaces. The proposed metric was developed within the framework of the European Active and Assisted Living research program, and was labeled "SB-STI for All." Extensive subjective in-Lab and in vivo tests have been conducted and the proposed metric proved to have a good correlation with subjective intelligibility scores.

Effect of age-related hearing loss on the click-rate-induced facilitation of acoustic reflex thresholds.

OBJECTIVE: This investigation was designed to evaluate the effect of age-related hearing loss on the click-rate-induced improvement in the acoustic reflex thresholds. DESIGN: Case-control study. STUDY SAMPLE: Data from five different adults ear-groups (15 ears each) were included in the study: 1. Younger with normal hearing. 2. Older with normal hearing. 3. Older with mild high-frequency loss. 4. Older with moderate high-frequency loss. 5. Older with low- and high-frequency loss. Ipsilateral acoustic reflex thresholds were obtained from the left and/or right ear/s by presenting clicks at the repetition rates of 50, 100, 150, 200 and 300 clicks/s. The rate-induced facilitation (RIF) was calculated by subtracting the lowest acoustic reflex threshold from the highest reflex threshold obtained across the various click-rates. RESULTS: The click-RIF is significantly reduced in older individuals compared to younger adults. There is no significant difference in RIF across the four older adult groups suggesting that an age-related, mild to moderate hearing loss has no significant effect on the click RIF of the acoustic reflex thresholds. CONCLUSIONS: Click-RIF may allow us to document the effect of ageing on temporal processing within the auditory brainstem area, in a time-efficient and objective manner using commercially available equipment.

Conversation breakdowns in the audiology clinic: the importance of mutual gaze.

BACKGROUND: Conversational breakdowns are a persistent concern for older adults with hearing impairment (HI). Previous studies in experimental settings have investigated potential causes of breakdowns in conversations with a person with HI, and effective strategies for repairing these breakdowns. However, little research has explored the causes of hearing-related communication breakdowns, and their repairs, in extended, naturally occurring conversations in a healthcare setting. AIMS: To analyse systematically instances of clients' initiations of repair within video-recorded initial audiology appointments, and to examine the interactional environment in which they occurred. METHODS & PROCEDURES: Participants included 26 audiologists and their older adult clients (aged 55+ years). Companions were present in 17 of the 63 appointments. Conversation analysis (CA) was used to examine the video-recorded audiology appointments with older adults with HI. The corpus was systematically analysed for all instances of 'other-initiated repair' by clients (initiation of repair targeting the prior speakers' turn). A collection of 51 instances of other-initiated repair were identified. These instances were analysed in detail for: (1) the interactional environment in which they occurred; (2) the strategy by which the client initiated repair; and (3) the strategies used by the audiologist to repair the communication breakdown. OUTCOMES & RESULTS: In 76% (n = 39) of the 51 cases of other-initiated repair from the client, there was a lack of mutual gaze between participants (i.e., either the audiologist or the client were looking away or facing in another direction during the prior turn). More specifically, many of these instances occurred when the audiologist was speaking to the client while multitasking. Audiologists used multiple-repair strategies in their responsive turn in an attempt to repair the communication breakdown efficiently. CONCLUSIONS & IMPLICATIONS: These findings, from extended, naturally occurring conversations with older adults with HI in clinic settings, highlight the importance of face-to-face communication even in quiet one-to-one settings. Clinicians should remain aware of their movements and gaze when speaking to clients during appointments. The findings also provide further support for the importance of communication programs in hearing rehabilitation.

[Speech intelligibility in elderly hearing impaired people].

The results of studying the features of auditory perception of speech stimuli in aged patients with hearing loss are presented in the article. 145 patients with moderate to severe sensorineural hearing loss from 52 to 90 years old underwent the tonal threshold audiometry and the tests battery to evaluate central auditory pathways functioning: the gap detection test, frequency difference limens, masking level difference, dichotic digits test. After analyzing speech discrimination scores of monosyllable words in quiet and in noise significantly worse results of all listeners in comparison with listeners with normal hearing are revealed; the deterioration of speech discrimination scores depending on age is noted. The impairment of speech discrimination is maximal when the speech stimuli are presented in background noise. Direct correlation between the deterioration of speech discrimination and the degree of hearing loss, it's duration, the presence of central auditory pathways dysfunction was ascertained.

Evaluation of serum antioxidants in age-related hearing loss.

BACKGROUND: Age-related hearing loss (ARHL) has been linked to the shift in the pro-oxidant/antioxidant ratio. Our objectives were to assess serum levels of retinol and zinc among the elderly individuals and to correlate the levels with hearing threshold. METHODS: Prospective study of apparently healthy individuals aged ≥60 years of age. Participants had complete clinical history, physical examination and pure tone average conducted. Blood samples were collected for determination of serum levels of retinol and zinc. Mann-Whitney U test was used to compare retinol and zinc values. Pearson's correlation test was used to determine the relationship between hearing threshold and serum levels of retinol and zinc. RESULTS: Among 126 elderly participants with mean age 67 ± 2.7 years; the mean pure tone average for air conduction was 29.3 ± 1.6 dBHL while the mean bone conduction was 36.5 ± 1.8 dBHL. The median values of serum retinol and zinc levels in the elderly participants who had hearing loss in the speech frequencies were 52 and 83.3 µg/L, respectively, while among participants with normal hearing threshold, values were 50 and 89.9 µg/L, respectively (p = 0.59 and 0.99, respectively). For the high frequencies, the median value of serum retinol and zinc levels among the elderly participants with normal hearing threshold was 70.3 and 99.9 µg/L, while among those with hearing loss, it was 46.9 and 83.2 µg/L, respectively (p = 0.000 and 0.005, respectively). CONCLUSION: Serum retinol and zinc levels were significantly lower among elderly with hearing loss involving the high frequencies. This is added evidence to extant literature on the possible role of antioxidants in the development of ARHL and suggests further study on the effect of antioxidants supplementation in the control of ARHL which is presently controversial and inconclusive.

Age effects in discrimination of intervals within rhythmic tone sequences.

This study measured listener sensitivity to increments of a target inter-onset interval (IOI) embedded within tone sequences that featured different rhythmic patterns. The sequences consisted of six 50-ms 1000-Hz tone bursts separated by silent intervals that were adjusted to create different timing patterns. Control sequences were isochronous, with all tonal IOIs fixed at either 200 or 400 ms, while other patterns featured combinations of the two IOIs arranged to create different sequential tonal groupings. Duration difference limens in milliseconds for increments of a single sequence IOI were measured adaptively by adjusting the duration of an inter-tone silent interval. Specific target IOIs within sequences differed across discrimination conditions. Listeners included younger normal-hearing adults and groups of older adults with and without hearing loss. Discrimination performance measured for each of the older groups of listeners was observed to be equivalent, with each group exhibiting significantly poorer discrimination performance than the younger listeners in each sequence condition. Additionally, the specific influence of variable rhythmic grouping on temporal sensitivity was found to be greatest among older listeners.

Sentence intelligibility during segmental interruption and masking by speech-modulated noise: Effects of age and hearing loss.

This study investigated how single-talker modulated noise impacts consonant and vowel cues to sentence intelligibility. Younger normal-hearing, older normal-hearing, and older hearing-impaired listeners completed speech recognition tests. All listeners received spectrally shaped speech matched to their individual audiometric thresholds to ensure sufficient audibility with the exception of a second younger listener group who received spectral shaping that matched the mean audiogram of the hearing-impaired listeners. Results demonstrated minimal declines in intelligibility for older listeners with normal hearing and more evident declines for older hearing-impaired listeners, possibly related to impaired temporal processing. A correlational analysis suggests a common underlying ability to process information during vowels that is predictive of speech-in-modulated noise abilities. Whereas, the ability to use consonant cues appears specific to the particular characteristics of the noise and interruption. Performance declines for older listeners were mostly confined to consonant conditions. Spectral shaping accounted for the primary contributions of audibility. However, comparison with the young spectral controls who received identical spectral shaping suggests that this procedure may reduce wideband temporal modulation cues due to frequency-specific amplification that affected high-frequency consonants more than low-frequency vowels. These spectral changes may impact speech intelligibility in certain modulation masking conditions.

Effects of age and hearing loss on the intelligibility of interrupted speech.

How age and hearing loss affect the perception of interrupted speech may vary based on both the physical properties of preserved or obliterated speech fragments and individual listener characteristics. To investigate perceptual processes and interruption parameters influencing intelligibility across interruption rates, participants of different age and hearing status heard sentences interrupted by silence at either a single primary rate (0.5-8 Hz; 25%, 50%, 75% duty cycle) or at an additional concurrent secondary rate (24 Hz; 50% duty cycle). Although age and hearing loss significantly affected intelligibility, the ability to integrate sub-phonemic speech fragments produced by the fast secondary rate was similar in all listener groups. Age and hearing loss interacted with rate with smallest group differences observed at the lowest and highest interruption rates of 0.5 and 24 Hz. Furthermore, intelligibility of dual-rate gated sentences was higher than single-rate gated sentences with the same proportion of retained speech. Correlations of intelligibility of interrupted speech to pure-tone thresholds, age, or measures of working memory and auditory spectro-temporal pattern discrimination were generally low-to-moderate and mostly nonsignificant. These findings demonstrate rate-dependent effects of age and hearing loss on the perception of interrupted speech, suggesting complex interactions of perceptual processes across different time scales.

Effects of age and hearing loss on recognition of unaccented and accented multisyllabic words.

The effects of age and hearing loss on recognition of unaccented and accented words of varying syllable length were investigated. It was hypothesized that with increments in length of syllables, there would be atypical alterations in syllable stress in accented compared to native English, and that these altered stress patterns would be sensitive to auditory temporal processing deficits with aging. Sets of one-, two-, three-, and four-syllable words with the same initial syllable were recorded by one native English and two Spanish-accented talkers. Lists of these words were presented in isolation and in sentence contexts to younger and older normal-hearing listeners and to older hearing-impaired listeners. Hearing loss effects were apparent for unaccented and accented monosyllabic words, whereas age effects were observed for recognition of accented multisyllabic words, consistent with the notion that altered syllable stress patterns with accent are sensitive for revealing effects of age. Older listeners also exhibited lower recognition scores for moderately accented words in sentence contexts than in isolation, suggesting that the added demands on working memory for words in sentence contexts impact recognition of accented speech. The general pattern of results suggests that hearing loss, age, and cognitive factors limit the ability to recognize Spanish-accented speech.

Determinants of hearing-aid adoption and use among the elderly: a systematic review.

OBJECTIVE: While the benefits of hearing aids among older adults with presbycusis have been well documented, there is limited research on hearing-aid usage. The aim of this review is to synthesize current evidence to identify the determinants of hearing-aid adoption and use among the elderly. DESIGN: Systematic review. STUDY SAMPLE: Articles were identified through systematic searches in the Web of Science, Medline, CINAHL, and a manual search. Studies that explore the potential determinants of hearing-aid usage were to be included. RESULTS: A total of twenty-two articles were reviewed. Four audiological determinants (the severity of hearing loss, the type of hearing aids, background noise acceptance, and insertion gain) and seven non-audiological determinants (self-perceived hearing problems, expectation, demographics, group consultation, support from significant others, self-perceived benefit, and satisfaction) were identified as affecting the adoption and use of hearing aids. CONCLUSIONS: There is a need to explore the influence of significant others, health professionals, and user demographics on hearing rehabilitation for future research. The determinants identified in this review depicted the stage progression of the trans-theoretical model (TTM) in explaining an individual's readiness to hearing-aid usage.

[Surgical Risk Profile and Audiological Outcome in the Elderly after Cochlea-implantation]. / Operatives Risikoprofil und Hör-Spracherfolg bei älteren Cochlea-Implantat-Patienten.

BACKGROUND: The number of elderly patients with indication for cochlear implantation is increasing. Our aim was to investigate whether seniors with cochlea implants differ from younger patients with regard to hearing improvement, surgical complications and rehabilitation. PATIENTS AND METHODS: Patients older than 60 years (ys) having received a cochlea implant in 2007-2012 were included (Group I 60-70 ys; Group II <70 ys). Preoperative risk factors according to ASA-Criteria and postoperative complications were analyzed. Improvements in quality of live were evaluated by questionnaire. Audiological outcome was tested by Freiburger speech test and OLSA sentence test with background noise. Patients with comparable conditions for cochlea implantation between 40 and 59 years of age served as control group (Group K). RESULTS: Patient cohort consisted of 94 patients, 29 of which being older than 70 years. Severe complications were inexistent postoperatively. Gr. II achieved a speech perception for numbers of 95% (65 dB) and 50% (65 dB) for monosyllables. The speech perception in Gr. II was not significantly different from Gr. I or K. According to the quality of life test all groups experienced an improvement in their social life. CONCLUSION: Old age itself is no contraindication to cochlea implantation. It has little influence on the postoperative speech perception even though the learning curve of the elderly rises slower. However, careful assessment with regard to surgical risk factors and expected outcome is necessary.

Managing age-related hearing loss: how to use hearing aids efficiently - a mini-review.

Using hearing aids may contribute to better functioning in the everyday lives of hearing-impaired older individuals. We introduce an integrative concept for the efficient use of hearing aids that involves both satisfaction with, and behaviour towards, hearing aids. We review theoretical and empirical work on the predictors of the efficient use of hearing aids in everyday life. Furthermore, we contend that the use of hearing aids requires improved understanding of the variability of hearing demands within specific contexts of everyday life (e.g. conversation with family members, listening to music). The efficiency of hearing aid use thus depends on the fit of situational demands, personal resources, and the specific configuration of the hearing aid device. We propose an integrative person-environment-fit model that advances concepts of selection, optimisation, and compensation to hearing aid efficiency. We discuss the implications of this model for research and for practitioners in the field of gerontology.

The role of stimulus complexity, spectral overlap, and pitch for gap-detection thresholds in young and old listeners.

Thresholds for detecting a gap between two complex tones were determined for young listeners with normal hearing and old listeners with mild age-related hearing loss. The leading tonal marker was always a 20-ms, 250-Hz complex tone with energy at 250, 500, 750, and 1000 Hz. The lagging marker, also tonal, could differ from the leading marker with respect to fundamental frequency (f0), the presence versus absence of energy at f0, and the degree to which it overlapped spectrally with the leading marker. All stimuli were presented with steeper (1 ms) and less steep (4 ms) envelope rise and fall times. F0 differences, decreases in the degree of spectral overlap between the markers, and shallower envelope shape all contributed to increases in gap-detection thresholds. Age differences for gap detection of complex sounds were generally small and constant when gap-detection thresholds were measured on a log scale. When comparing the results for complex sounds to thresholds obtained for pure-tones in a previous study by Heinrich and Schneider [(2006). J. Acoust. Soc. Am. 119, 2316-2326], thresholds increased in an orderly fashion from markers with identical (within-channel) pure tones to different (between-channel) pure tones to complex sounds. This pattern of results was true for listeners of both ages although younger listeners had smaller thresholds overall.

Effects of age and hearing loss on stream segregation based on interaural time differences.

The effect of interaural time differences (ITDs) on obligatory stream segregation for successive tone bursts was investigated for older listeners with normal hearing (ONH) and hearing loss (OHL), by measuring the threshold for detecting a rhythmic irregularity in an otherwise isochronous sequence of interleaved "A" and "B" tones. The A and B tones had equal but opposite ITDs from 0 to 0.5 ms. For some of the ONH listeners, the threshold increased with increasing ITD, but no OHL listener showed an effect of ITD. It is concluded that hearing loss reduces the potency of ITDs in inducing obligatory stream segregation.

Inflammation is associated with a worsening of presbycusis: evidence from the MRC national study of hearing.

OBJECTIVE: Inflammaging, a state of chronic inflammation in the elderly, is now thought to be a key element of the ageing process and contributor to age-related disease. In a previously published study, we identified a significant association between inflammation levels and severity of presbycusis among individuals aged 63 to 73 ('younger old") within an available audiometric range 0.5 to 4 kHz. Our aim was to see if this association would be identified among participants in the MRC national study of hearing, and whether the strength of the association would increase with greater age, or for very low or very high audiometric frequencies. DESIGN: Cross-sectional analysis of cohort data. STUDY SAMPLE: Three hundred and sixty community-dwelling adults age 60 years and over, representing all those with white blood cell count and audiometric data available. RESULTS: A significant independent association between (higher) WBC and (worse) hearing level was identified. This effect increased with age. The strongest association was among those over 75, for whom average hearing threshold levels among those with lower WBC was 17 dB better than those with higher WBC. CONCLUSIONS: The current findings support an association between inflammaging (a condition potentially amenable to pharmacological treatment or lifestyle management) and presbycusis.