Prevalence of Central Auditory Processing (CAP) Abnormality in an Older Australian Population: The Blue Mountains Hearing Study

Toward Sound Localization Testing in Virtual Reality to Aid in the Screening of Auditory Processing Disorders

Sound localization testing is key for comprehensive hearing evaluations, particularly in cases of suspected auditory processing disorders. However, sound localization is not commonly assessed in clinical practice, likely due to the complexity and size of conventional measurement systems, which require semicircular loudspeaker arrays in large and acoustically treated rooms. To address this issue, we investigated the feasibility of testing sound localization in virtual reality (VR). Previous research has shown that virtualization can lead to an increase in localization blur. To measure these effects, we conducted a study with a group of normal-hearing adults, comparing sound localization performance in different augmented reality and VR scenarios. We started with a conventional loudspeaker-based measurement setup and gradually moved to a virtual audiovisual environment, testing sound localization in each scenario using a within-participant design. The loudspeaker-based experiment yielded results comparable to those reported in the literature, and the results of the virtual localization test provided new insights into localization performance in state-of-the-art VR environments. By comparing localization performance between the loudspeaker-based and virtual conditions, we were able to estimate the increase in localization blur induced by virtualization relative to a conventional test setup. Notably, our study provides the first proxy normative cutoff values for sound localization testing in VR. As an outlook, we discuss the potential of a VR-based sound localization test as a suitable, accessible, and portable alternative to conventional setups and how it could serve as a time- and resource-saving prescreening tool to avoid unnecessarily extensive and complex laboratory testing.

Auditory Processing Disorder: Protocols and Controversy

PURPOSE

This study examined current auditory processing disorder (APD) protocols and audiologists' perspectives on the active debate seen in the literature regarding the status of APD as a unique disorder.

METHOD

This study used a cross-sectional, nonexperimental survey design. The participants were 134 U.S. audiologists, representing diversity across experience level and work setting.

RESULTS

Popular APD tests from prior surveys remain popular, and a few new tests have emerged. Most audiologists use diverse strategies to identify potential comorbid disorders as part of their APD protocol, including multidisciplinary assessment and referral to other specialists. Most participants disagreed with the assertion that APD is not a unique disorder; however, many also pointed out that patients' struggles with listening need to be the primary focus of APD assessment and management, regardless of the label of the disorder. Qualitative analysis of participant comments on the controversy yielded six themes: Clinical Experience, Comorbidity, Listening Skills, Literature Support, Overdiagnosis, and More Information Needed.

CONCLUSION

Most participants consider APD to be a unique disorder, citing clinical experience and the literature for support; however, many also indicated APD is complicated by comorbidity and APD may be overdiagnosed.

Central Auditory Processing Dysfunction in Service Members and Veterans: Treatment Considerations and Strategies

PURPOSE

Military risk factors such as blast exposure, noise exposure, head trauma, and neurotoxin exposure place Service members and Veterans at risk for deficits associated with auditory processing dysfunction. However, there is no clinical guidance specific to the treatment of auditory processing deficits in this unique population. We provide an overview of available treatments and their limited supporting evidence for use in adults, emphasizing the need for multidisciplinary case management and interdisciplinary research to support evidence-based solutions.

METHOD

We explored relevant literature to inform the treatment of auditory processing dysfunction in adults, with emphasis on findings involving active or former military personnel. We were able to identify a limited number of studies, pertaining primarily to the treatment of auditory processing deficits through the use of assistive technologies and training strategies. We assessed the current state of the science for knowledge gaps that warrant additional study.

CONCLUSIONS

Auditory processing deficits often co-occur with other military injuries and may pose significant risk in military operational and occupational settings. Research is needed to advance clinical diagnostic and rehabilitative capabilities, guide treatment planning, support effective multidisciplinary management, and inform fitness-for-duty standards. We emphasize the need for an inclusive approach to the assessment and treatment of auditory processing concerns in Service members and Veterans and for evidence-based solutions to address complex military risk factors and injuries.

A review of auditory processing and cognitive change during normal ageing, and the implications for setting hearing aids for older adults

Throughout our adult lives there is a decline in peripheral hearing, auditory processing and elements of cognition that support listening ability. Audiometry provides no information about the status of auditory processing and cognition, and older adults often struggle with complex listening situations, such as speech in noise perception, even if their peripheral hearing appears normal. Hearing aids can address some aspects of peripheral hearing impairment and improve signal-to-noise ratios. However, they cannot directly enhance central processes and may introduce distortion to sound that might act to undermine listening ability. This review paper highlights the need to consider the distortion introduced by hearing aids, specifically when considering normally-ageing older adults. We focus on patients with age-related hearing loss because they represent the vast majority of the population attending audiology clinics. We believe that it is important to recognize that the combination of peripheral and central, auditory and cognitive decline make older adults some of the most complex patients seen in audiology services, so they should not be treated as "standard" despite the high prevalence of age-related hearing loss. We argue that a primary concern should be to avoid hearing aid settings that introduce distortion to speech envelope cues, which is not a new concept. The primary cause of distortion is the speed and range of change to hearing aid amplification (i.e., compression). We argue that slow-acting compression should be considered as a default for some users and that other advanced features should be reconsidered as they may also introduce distortion that some users may not be able to tolerate. We discuss how this can be incorporated into a pragmatic approach to hearing aid fitting that does not require increased loading on audiology services.

Potential Risks to Hearing Functions of Service Members From Exposure to Jet Fuels

Purpose Several military occupations, particularly those within the U.S. Air Force, require working with or around jet fuels. Jet fuels contain components that are known to affect central nervous function, yet effects of these fuels on auditory function, specifically auditory processing of sound, are not well understood at this time. Animal studies have demonstrated that exposure to jet fuels prior to noise exposure can exacerbate the noise exposure's effects, and service members exposed to jet fuels are at risk of noise exposure within their work environments. The purpose of this article was to give a brief synopsis of the evidence on the ototoxic effects due to jet fuel exposure to aid audiologists in their decision making when providing care for populations who are occupationally exposed to fuels or while during military service. Conclusions Exposure to jet fuels impacts central nervous function and, in combination with noise exposure, may have detrimental auditory effects that research has yet to fully explain. Additional longitudinal research is needed to explain the relationships, which have clinical implications for service members and others exposed to jet fuels. In the meantime, audiologists can gain useful information by screening for chemical exposures when obtaining patient case histories. If jet fuel exposure is suspected, the Lifetime Exposure to Noise and Solvents Questionnaire can be used to estimate a noise exposure ranking and identify other potentiating agents such as jet fuel and industrial chemicals. A history of jet fuel exposure should inform the selection of hearing tests in the audiometric evaluation and when devising the treatment plan.

Longitudinal Decline on the Dichotic Digits Test

Purpose The dichotic digits test (DDT) is commonly administered in clinical and research settings, but it is not well understood how performance changes in aging. The purpose of this study is to determine the 5-year change on the free recall task and right ear advantage (REA) in a population-based cohort and factors associated with change. Method Participants in the population-based Epidemiology of Hearing Loss Study, who completed the DDT during the fourth (2009-2010) and fifth (2013-2016) examination periods were included (n = 865, M _age = 72.8 years at baseline). Free recall DDT was administered using 25 sets of triple-digit pairs presented at 70 dB HL. The REA was calculated by subtracting the score in the left ear from the score in the right ear. Results In 5 years, most participants (62.4%) declined on free recall performance (mean decline = 3.0% [4.5 digits], p < .01). In age-sex-adjusted models, higher baseline scores, hearing impairment, and lower education were significantly associated with increased risk of decline. An REA at baseline (76.8%) and follow-up (77.9%) was common. Half of participants (50.6%) had a 5-year REA widening (M = 1.9% [1.4 digits], p = .01). Older age, but not hearing impairment, was associated with increased risk of REA widening. Conclusions The 5-year decline on free recall recognition performance was not associated with age but was associated with hearing impairment, whereas the 5-year widening of REA was associated with age but not hearing impairment. These results indicate that the REA may be a more sensitive measure of aging of the central auditory system than free recall performance.

Are auditory processing and cognitive performance assessments overlapping or distinct? Parsing the auditory behaviour of older adults

OBJECTIVE

Auditory processing predicts cognitive decline, including dementia, in older adults. Auditory processing involves the understanding, interpretation, and communication of auditory information. Cognition is linked to auditory processing; however, it is disputed whether auditory processing is a separate construct distinct from cognition. The purpose of this study was to determine if auditory processing is distinct from cognition in older adults.

DESIGN

Participants completed 14 cognitive and auditory processing assessments. Assessments were subjected to exploratory factor analysis with principal components extraction and varimax rotation with Kaiser normalisation. Study sample: 213 community-dwelling older adults (M = 71.39 years, 57% female, 93% Caucasian, M = 16 years education) with and without mild cognitive impairment (MCI) participated.

RESULTS

Four factors were identified, explaining 66.3% of the total variance: (1) executive functions, visual processing speed, and dichotic auditory processing, (2) auditory processing of degraded speech, (3) memory, and (4) auditory temporal processing of nonspeech.

CONCLUSIONS

Two domains of auditory processing (processing degraded speech and temporal processing) account for unique variance to which cognitive measures are not sensitive, while measures of auditory dichotic processing appear to be tapping similar abilities as measures of cognition. Older adults who perform poorly on dichotic measures should be screened for cognitive impairment.

Examining the Validity of the World Health Organization's Long-Standing Hearing Impairment Grading System for Unaided Communication in Age-Related Hearing Loss

Objective

This review article overviews a presentation at the Hearing Across the Lifespan 2018 Conference, which examined the data from 5 data sets having pure-tone thresholds and functional measures of speech communication from relatively large groups of older adults to evaluate the validity of the long-standing World Health Organization (WHO) hearing impairment (HI) grading system.

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 data sets and 2 clinical data sets were identified and included in the review.

Results

As the WHO-HI 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 all other WHO-HI grades. This was true for self-report measures of speech communication and direct measures of speech recognition in quiet and noise. Cohen's d effect sizes were moderate to very large between each successive step on the WHO-HI grading scale.

Conclusions

The long-standing WHO-HI grading system, developed through expert opinion and adopted by WHO originally in 1991, is validated here with evidence from studies of functional communication in older adults. The WHO-HI grade system is compared to a proposed new WHO-HI grade system that introduces several changes to the grading system.

Case studies of adults with central auditory processing disorder: Shifting the spotlight!

Vast literature exists detailing the identification and management of central auditory processing disorder in children: however, less information is available regarding central auditory processing disorder in the adult population. This study aimed to document the diagnostic and management procedure for adults presenting at a multidisciplinary clinic due to concerns regarding their listening and central auditory processing skills. This retrospective study was a case file audit of two adults (a male, aged 37 years and a female, aged 44 years) who presented at a multidisciplinary (audiology and speech pathology) clinic for a hearing and central auditory processing evaluation. Both participants completed a case history questionnaire and were then interviewed with results being documented in their file. Participants were evaluated by a dually qualified audiologist-speech pathologist on a battery of peripheral hearing tests (including pure-tone threshold audiometry, immittance measures and speech tests), central auditory processing assessments (including monaural low redundancy, dichotic listening and temporal processing tests) and evaluation of short-term auditory memory skills. Participants were self-referred, never having been assessed previously for central auditory processing disorder, yet had perceived heightened difficulty with processing information; having conversations (particularly in noisy work or social environments) and remembering information, resulting in a range of psychosocial responses. Following diagnosis of central auditory processing disorder, participants undertook an individualized short-term aural rehabilitation program as dictated by their needs and preferences. Post-program participants perceived better ability to listen and process information even in adverse listening conditions. They reported that their newly learned skills improved their work abilities and social participation leading to positive outcomes. Medical and other allied health professionals should consider the possibility of presentation of central auditory processing disorder in adulthood and make appropriate referrals for central auditory processing testing to facilitate diagnosis and appropriate intervention. Aural rehabilitation should be considered for adults newly diagnosed with central auditory processing disorder.

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.

The risk of cognitive impairment associated with hearing function in older adults: a pooled analysis of data from eleven studies

Impaired hearing and cognition are disabling conditions among older adults. Research has presented inconsistent conclusions regarding hearing impairment posing a risk for cognitive impairment. We aimed to assess this from published evidence via searching PubMed and Embase, from the inception of the databases indexed to December 2, 2016. For those high-quality studies retrieved, relative risk (RR) and 95% confidence intervals (CIs) were combined to estimate the risk of cognitive impairment. Eleven cohort studies were included in the present study. Pooled results found that elderly people with disabled peripheral and central hearing function had a higher risk of cognitive impairment (for moderate/severe peripheral hearing impairment: RR = 1.29, 95% CI: 1.04-1.59 during a follow-up ≤6 years. RR = 1.57, 95% CI: 1.13-2.20 during a follow-up >6 years; for severe central hearing impairment, RR = 3.21, 95% CI: 1.19-8.69) compared to those with normal hearing function. We also recorded a dose-response trend for cognitive impairment as hearing thresholds rose. No evident bias from potential confounding factors was found with one exception: the length for clinical follow-up. Although results are preliminary because qualifying studies were few, statistical findings were consistent with older people identified as having greater levels of hearing loss, having a corresponding higher risk of cognitive impairment.

Auditory Processing of Older Adults With Probable Mild Cognitive Impairment

PURPOSE

Studies suggest that deficits in auditory processing predict cognitive decline and dementia, but those studies included limited measures of auditory processing. The purpose of this study was to compare older adults with and without probable mild cognitive impairment (MCI) across two domains of auditory processing (auditory performance in competing acoustic signals and temporal aspects of audition).

METHOD

The Montreal Cognitive Assessment (Nasreddine et al., 2005) was used to classify participants as with or without probable MCI. In this cross-sectional study, participants (n = 79) completed 4 measures of auditory processing: Synthetic Sentence Identification with Ipsilateral Competing Message (Gates, Beiser, Rees, D'Agostino, & Wolf, 2002), Dichotic Sentence Identification (Fifer, Jerger, Berlin, Tobey, & Campbell, 1983), Adaptive Tests of Temporal Resolution (ATTR; Lister & Roberts, 2006; across-channel and within-channel subtests), and time-compressed speech (Wilson, 1993; Wilson, Preece, Salamon, Sperry, & Bornstein, 1994). Audiometry was also conducted.

RESULTS

Those with probable MCI had significantly poorer performance than those without MCI on Synthetic Sentence Identification with Ipsilateral Competing Message, Dichotic Sentence Identification, and the ATTR within-channel subtest. No group differences were found for time-compressed speech, ATTR across-channel, or audiometric measures.

CONCLUSIONS

Older adults with cognitive impairment not only have difficulty with competing acoustic signals but may also show poor temporal processing. The profile of auditory processing deficits among older adults with cognitive impairment may include multiple domains.

Mechanisms of the Hearing-Cognition Relationship

This review provides a description of age-related changes in hearing and cognition, the relationship between hearing and cognition, and several potential mechanisms that underlie the relationship. Several studies have shown a significant relationship between peripheral hearing loss and cognitive impairment/decline but other studies have not. Furthermore, poor performance on measures of central auditory processing has been significantly associated with cognitive impairment. Important to understanding these relationships are the nature of the underlying mechanisms. Possible mechanisms are overdiagnosis, widespread neural degeneration, sensory degradation/deprivation, cognitive resource allocation/depletion, and social isolation/depression. Overdiagnosis occurs when hearing loss impacts tests of cognitive function or vice versa. Widespread neural degeneration can impact hearing, cognition, or both. Sensory degradation/deprivation due to hearing loss can result in neural degradation and reduced cognitive function. Increased demands due to hearing loss can result in changes in neural resource allocation, reducing available resources for cognitive function. Finally, hearing difficulties can cause social isolation and even depression, increasing the risk for cognitive decline. Data from our laboratory provide support for cognitive resource allocation/depletion. Understanding all five of these mechanisms will advance the development of effective interventions and treatments, thereby enhancing the quality of life of older adults.

Central auditory processing disorders in children and adults

Central auditory processing disorders (CAPD) can affect children and adults of all ages due to a wide variety of causes. CAPD is a neurobiologic deficit in the central auditory nervous system (CANS) that affects those mechanisms that underlie fundamental auditory perception, including localization and lateralization; discrimination of speech and non-speech sounds; auditory pattern recognition; temporal aspects of audition, including integration, resolution, ordering, and masking; and auditory performance with competing and/or degraded acoustic signals (American Speech-Language-Hearing Association, 2005a, b). Although it is recognized that central auditory dysfunction may coexist with other disorders, CAPD is conceptualized as a sensory-based auditory disorder. Administration of behavioral and/or electrophysiologic audiologic tests that have been shown to be sensitive and specific to dysfunction of the CANS is critical for a proper diagnosis of CAPD, in addition to assessments and collaboration with a multidisciplinary team. Intervention recommendations for CAPD diagnosis are based on the demonstrated auditory processing deficits and related listening and related complaints. This chapter provides an overview of current definitions and conceptualizations, methods of diagnosis of, and intervention for, CAPD. The chapter culminates with a case study illustrating pre- and posttreatment behavioral and electrophysiologic diagnostic findings.

Methods to eliminate stimulus transduction artifact from insert earphones during electroencephalography

OBJECTIVE

To reduce stimulus transduction artifacts in EEG while using insert earphones.

DESIGN

Reference Equivalent Threshold SPLs were assessed for Etymotic ER-4B earphones in 15 volunteers. Auditory brainstem responses (ABRs) and middle latency responses (MLRs)-as well as long-duration complex ABRs-to click and /dα/ speech stimuli were recorded in a single-case design.

RESULTS

Transduction artifacts occurred in raw EEG responses, but they were eliminated by shielding, counter-phasing (averaging across stimuli 180° out of phase), or rereferencing.

CONCLUSIONS

Clinical grade ABRs, MLRs, and cABRs can be recorded with a standard digital EEG system and high-fidelity insert earphones, provided one or more techniques are used to remove the stimulus transduction artifact.

Dichotic word recognition in noise and the right-ear advantage

PURPOSE

This study sought to compare dichotic right-ear advantages (REAs) of young adults to older adult data (C. M. Roup, T. L. Wiley, & R. H. Wilson, 2006) after matching for overall levels of recognition performance. Specifically, speech-spectrum noise was introduced in order to reduce dichotic recognition performance of young adults to a level consistent with that of older adults with hearing loss.

METHOD

Dichotic word-recognition performance was evaluated in the free-recall response paradigm across 2 conditions: (a) quiet and (b) noise (+11 dB signal-to-noise ratio). Participants included a group of right-handed young adults (n = 32) with normal hearing.

RESULTS

The introduction of noise resulted in significantly poorer dichotic word-recognition performance than in the quiet condition for the young adults. REAs, however, did not differ between the 2 conditions. Relative to the Roup et al. (2006) older adult data, performance of the young adults in the noise condition resulted in (a) similar levels of overall recognition performance and (b) significantly smaller REAs.

CONCLUSIONS

Results suggest that the magnitude of the REA is not dependent upon the difficulty of the dichotic task. Rather, the large REAs exhibited by older adults are more likely related to age-related deficits in auditory processing.

Percepção de fala em idosos: análise dos erros

OBJETIVO: analisar os erros apresentados em um teste de fala na presença de ruído competitivo de idosos. MÉTODO: foi realizado estudo retrospectivo com levantamento de dados de prontuário de 55 idosos divididos em grupo controle (GC) e grupo estudo (GE), considerando os testes Índice Percentual de Reconhecimento de Fala (IPRF) e Fala com Ruído (F/R). RESULTADO: as trocas articulatórias foram mais frequentes no GE e no teste F/R. De maneira geral, ocorreram mais omissões de fonemas na posição inicial (/p/ e /b/) e final (/s/) dos vocábulos, principalmente com o ruído. Houve omissões de vocábulos somente no GE. Os vocábulos mais trocados no GC foram "rir ", "dil ", "lhe ", "faz " e "rol ", e no GE, "rir ", "dil ", "lhe ", "faz ", "pus " e "rol ". CONCLUSÃO: a presença de limiares tonais normais não impediu que ocorressem erros no reconhecimento de fala e o ruído interferiu negativamente neste reconhecimento, principalmente no idoso com perda auditiva. Os fonemas /p/, /b/ e /s/ foram os mais frequentemente omitidos, principalmente na presença do ruído competitivo. Os vocábulos "rir ", "dil ", "lhe ", "faz " e "rol " foram os mais trocados para os grupos avaliados, sobretudo na presença do ruído.

Hearing loss impacts on the use of community and informal supports

OBJECTIVE

the aim of this study is to estimate the cross-sectional and longitudinal impact of hearing loss on use of community support services and reliance on non-spouse family/friends among older people.

METHODS

Blue Mountains Hearing Study participants (n = 2,956) were assessed for hearing impairment by audiologists in sound-treated booths. Participants were classified as hearing impaired if PTA(0.5-4)( )(kHz) >25 dB HL. Use of services and non-spouse family/friend support was assessed cross-sectionally. Incident use was assessed among survivors at the 5-year follow-up (n = 1,457).

RESULTS

a significant cross-sectional association between hearing loss (>25 dB HL) and use of community support services was observed after adjusting for age, sex, living status, self-rated poor health, self-reported hospital admissions, disability in walking and best-corrected visual impairment [odds ratio (OR) 2.12, 95% confidence interval (CI) 1.15-3.90]. Participants with hearing loss who never used a hearing aid were twice as likely to use formal supports as participants without hearing loss (multivariate-adjusted OR 2.25, 95% CI 1.19-4.24). Hearing loss increased the incident need for non-spouse family/friend support or community services (multivariate-adjusted OR 1.49, 95% CI 1.02-2.18).

CONCLUSIONS

after adjusting for confounding factors, hearing impairment negatively impacted on the independence of older persons by increasing reliance on community or family support.

Auditory processing assessment in older people with no report of hearing disability

In the elderly, the results of central auditory pathways behavioral assessments are considered to be difficult to read because of the possible interference of peripheral auditory pathway involvement. Aim: Assess the efficacy of the central auditory function in elderly patients who do not complain of hearing. Materials and Methods: Case study involving 40 individuals within the age range of 60 to 75 years. The patients underwent auditory processing evaluation based on anamnesis, otorhinolaryngological exam, threshold tonal audiometry, speech recognition threshold, speech recognition index, immittance measures, stapes reflex study, synthetic phrases identification test with ipsilateral competitive message, frequency pattern test and alternate twin-syllable test through dichotic task; age range and hearing loss influenced results from the phrases identification with ipsilateral competitive message. Percentages of right answers below normal standards were seen in the three tests that assessed the central auditory functions. Conclusion: Elderly individuals who did not complain of hearing presented relevant prevalence of signs of central auditory function inefficiencies.

Avaliação do processamento auditivo em idosos que relatam ouvir bem

Em idosos, os resultados da avaliação comportamental das vias auditivas centrais são considerados de difícil interpretação devido à possível interferência do comprometimento das vias auditivas periféricas. OBJETIVO: Avaliar a eficiência das funções auditivas centrais de idosos que relatam ouvir bem. MATERIAL E MÉTODO: Estudo de casos que incluiu 40 indivíduos na faixa etária de 60 a 75 anos. Os pacientes foram submetidos à avaliação do processamento auditivo que constou de anamnese, exame otorrinolaringológico, audiometria tonal liminar, limiar de reconhecimento de fala, índice de reconhecimento de fala, imitanciometria, pesquisa de reflexos estapedianos, teste de identificação de sentenças sintéticas com mensagem competitiva ipsilateral, teste de padrões de freqüência e teste de dissílabos alternados por meio de tarefa dicótica. RESULTADOS: Gênero, faixa etária e perda auditiva não influenciaram os resultados dos testes de padrões de freqüência e dissílabos alternados por meio de tarefa dicótica; faixa etária e perda auditiva influenciaram os resultados do teste de identificação de sentenças com mensagem competitiva ipsilateral. Porcentagens de acertos abaixo dos padrões da normalidade de adultos foram observadas nos três testes que acessam as funções auditivas centrais. CONCLUSÃO: Indivíduos idosos que relatam ouvir bem apresentam prevalência relevante de sinais de ineficiência das funções auditivas centrais.

Longitudinal changes in speech recognition in older persons

Recognition of isolated monosyllabic words in quiet and recognition of key words in low- and high-context sentences in babble were measured in a large sample of older persons enrolled in a longitudinal study of age-related hearing loss. Repeated measures were obtained yearly or every 2 to 3 years. To control for concurrent changes in pure-tone thresholds and speech levels, speech-recognition scores were adjusted using an importance-weighted speech-audibility metric (AI). Linear-regression slope estimated the rate of change in adjusted speech-recognition scores. Recognition of words in quiet declined significantly faster with age than predicted by declines in speech audibility. As subjects aged, observed scores deviated increasingly from AI-predicted scores, but this effect did not accelerate with age. Rate of decline in word recognition was significantly faster for females than males and for females with high serum progesterone levels, whereas noise history had no effect. Rate of decline did not accelerate with age but increased with degree of hearing loss, suggesting that with more severe injury to the auditory system, impairments to auditory function other than reduced audibility resulted in faster declines in word recognition as subjects aged. Recognition of key words in low- and high-context sentences in babble did not decline significantly with age.

Odds of demonstrating auditory processing abnormality in the average older adult: the Blue Mountains Hearing Study

OBJECTIVE

To determine, for the average older adult, the odds of demonstrating an auditory processing abnormality for each of seven speech-based measures of auditory processing and how these odds vary based on a number of independent subject variables.

DESIGN

Using a cross-sectional design, 1576 adults aged 55 years and older were assessed with speech measures of central auditory processing and questionnaires pertaining to health status, cognitive and perceived auditory function. The speech-based measures from which abnormal/normal outcomes were derived were (a) right ear Macquarie Synthetic Sentence Identification (MSSI) test maximum performance score (Rt MSSImax), (b) left ear MSSI test maximum performance score (Lt MSSImax), (c) right ear Macquarie Dichotic Sentence Identification (MDSI) test score (Rt MDSI), (d) left ear MDSI test score (Lt MDSI), (e) difference score for the right and left ear MDSI test (MDSI Diff score), (f) right ear MSSI test maximum performance score subtracted from the maximum performance score for monosyllabic word list materials in the same ear (Rt PB-MSSImax), and (g) left ear MSSI test maximum performance score subtracted from the maximum performance score for monosyllabic word list materials in the same ear (Lt PB-MSSImax).

RESULTS

The odds of demonstrating auditory processing abnormality for average older participants, increased by 4 to 9% per year of age. Men were approximately twice as likely as women to demonstrate this abnormality, but the gender difference was only evident with dichotic measures. With increasing hearing handicap, the odds of demonstrating auditory processing abnormality increased, but this was only evident for speech-in-noise measures. With subtle cognitive decline, the odds of demonstrating auditory processing abnormality also increased.

CONCLUSIONS

This population-based study provides evidence of a link between perceived hearing handicap and outcomes on speech-in-noise measures as well as evidence of a gender difference that became apparent using dichotic tests. The contribution of central auditory processing abnormality to hearing health should therefore not be overlooked in the provision of auditory rehabilitation programs to older adults.