Sara K. Mamo

Processing of temporal fine structure as a function of age

Objectives: The purpose of this study was to determine whether the processing of temporal fine structure diminishes with age, even in the presence of relatively normal audiometric hearing. Temporal fine structure processing was assessed by measuring the discrimination of interaural phase differences (IPDs). The hypothesis was that IPD discrimination is more acute in middle-aged observers than in older observers but that acuity in middle-aged observers is nevertheless poorer than in young adults. Design: Two experiments were undertaken. The first measured discrimination of 0- and &pgr;-radian interaural phases as a function of carrier frequency. The stimulus was a 5-Hz sinusoidally amplitude-modulated tone in which, in the signal waveform, the interaural phase of the carrier was inverted during alternate modulation periods. The second experiment measured IPD discrimination at fixed frequencies. The stimulus was a pair of tone pulses in which, in the signal, the trailing pulse contained an IPD. A total of 39 adults with normal audiograms ≤2000 Hz participated in this study, of which 15 were younger, 12 middle aged, and 12 older. Results: Experiment 1 showed that the highest carrier frequency at which a &pgr;-radian IPD could be discriminated from the diotic, 0-radian standard was significantly lower in middle-aged listeners than young adults, and still lower in older listeners. Experiment 2 indicated that middle-aged listeners were less sensitive to IPDs than young adults at all but the lowest frequencies tested. Older listeners, as a group, had the poorest thresholds. Conclusions: These results suggest that deficits in temporal fine structure processing are evident in the presenescent auditory system. This adds to the accumulating evidence that deficiencies in some aspects of auditory temporal processing emerge relatively early in the aging process. It is possible that early-emerging temporal processing deficits manifest themselves in challenging speech in noise environments.

Age effects in temporal envelope processing: speech unmasking and auditory steady state responses

Objective: The purpose of this study was to determine whether temporal envelope processing is reduced in older listeners. Experiment 1 tested the hypothesis that older listeners exhibit reduced speech unmasking at higher modulation rates. Experiment 2 tested the hypothesis that auditory steady state response (ASSR) amplitudes are reduced in older listeners at high modulation rates. Design: Two groups of observers with relatively normal hearing (younger, mean age = 25.0 years and older, mean age = 68.7 years) participated in two experiments. Experiment 1 examined speech unmasking in modulated noise as a function of masker modulation rate (16 and 32 Hz) and target speech rate (normal and 33% time compressed). Experiment 2 measured ASSR amplitudes as a function of modulation rate (32 and 128 Hz) and carrier frequency (500 and 2000 Hz). Results: Experiment 1 indicated that older listeners show reduced speech unmasking for normal-rate speech and reduced recognition of rapid speech in steady noise. However, for rapid speech, there is no age effect for speech unmasking and no difference in the magnitude of masking release as a function of modulation rate. In general, effects of listener age and masker modulation rate on the magnitude of masking release are observed only for normal-rate speech. Experiment 2 showed that the ASSR amplitudes of older listeners are reduced for a 128-Hz modulation rate but not for a 32-Hz modulation rate, irrespective of carrier frequency. Conclusion: These results suggest that the reduced speech unmasking seen in older listeners for relatively slow modulation rates is not caused by deficits in envelope processing but rather is associated with the more constrained redundancy of the speech material available during the masker minima. Deficits in temporal envelope processing are evident in advanced age but only for relatively high envelope frequencies.

Electrophysiological measurement of binaural beats: effects of primary tone frequency and observer age.

Objective: The purpose of this study was to determine the reliability of the electrophysiological binaural beat steady state response as a gauge of temporal fine structure coding, particularly as it relates to the aging auditory system. The hypothesis was that the response would be more robust in a lower, than in a higher, frequency region and in younger, than in older, adults. Design: Two experiments were undertaken. The first measured the 40 Hz binaural beat steady state response elicited by tone pairs in two frequency regions: Lower (390 and 430 Hz tone pair) and higher (810 and 850 Hz tone pair). Frequency following responses (FFRs) evoked by the tones were also recorded. Ten young adults with normal hearing participated. The second experiment measured the binaural beat and FFRs in older adults but only in the lower frequency region. Fourteen older adults with relatively normal hearing participated. Response metrics in both experiments included response component signal-to-noise ratio (F statistic) and magnitude-squared coherence. Results: Experiment 1 showed that FFRs were elicited in both frequency regions but were more robust in the lower frequency region. Binaural beat responses elicited by the lower frequency pair of tones showed greater amplitude fluctuation within a participant than the respective FFRs. Experiment 2 showed that older adults exhibited similar FFRs to younger adults, but proportionally fewer older participants showed binaural beat responses. Age differences in onset responses were also observed. Conclusions: The lower prevalence of the binaural beat response in older adults, despite the presence of FFRs, provides tentative support for the sensitivity of this measure to age-related deficits in temporal processing. However, the lability of the binaural beat response advocates caution in its use as an objective measure of fine structure coding.

Personal Sound Amplifiers for Adults with Hearing Loss

Age-related hearing loss is highly prevalent and often untreated. Use of hearing aids has been associated with improvements in communication and quality of life, but such treatment is unaffordable or inaccessible for many adults. The purpose of this review is to provide a practical guide for physicians who work with older adults who are experiencing hearing and communication difficulties. Specifically, we review direct-to-consumer amplification products that can be used to address hearing loss in adults. Helping adults with hearing loss navigate hearing loss treatment options ranging from being professionally fitted with hearing aids to using direct-to-consumer amplification options is important for primary care clinicians to understand given our increasing understanding of the impact of hearing loss on cognitive, social, and physical functioning.

Hearing Loss Health Care for Older Adults

Hearing deficits are highly prevalent among older adults and are associated with declines in cognitive, physical, and mental health. However, hearing loss in the geriatric population often goes untreated and generally receives little clinical emphasis in primary care practice. This article reviews hearing health care for older adults, focusing on what is most relevant for family physicians. The objective of hearing loss treatment is to ensure that a patient can communicate effectively in all settings. We present the 5 major obstacles to obtaining effective hearing and rehabilitative care: awareness, access, treatment options, cost, and device effectiveness. Hearing technologies are discussed, along with recommendations on when it is appropriate to screen, refer, or counsel a patient. The purpose of this article is to provide pragmatic recommendations for the clinical management of the older adult with hearing loss that can be conducted in family medicine practices.

Hearing Care Intervention for Persons with Dementia: A Pilot Study

OBJECTIVE Hearing loss is a commonly unmet need among adults with dementia that may exacerbate common dementia-related behavioral symptoms. Accessing traditional audiology services for hearing loss is a challenge because of high cost and time commitment. To improve accessibility and affordability of hearing treatment for persons with dementia, there is a need for unique service delivery models. The purpose of this study is to test a novel hearing intervention for persons with dementia and family caregivers delivered in outpatient settings. METHODS The Memory-HEARS pilot study delivered a 2-hour in-person intervention in an outpatient setting. A trained interventionist provided hearing screening, communication strategies, and provision of and instruction using a simple over-the-counter amplification device. Caregivers (N = 20) responded to questionnaires related to depression, neuropsychiatric symptoms, and caregiver burden at baseline and 1-month postintervention. RESULTS Overall, caregivers believed the intervention was beneficial, and most participants with dementia wore the amplification device daily. For the depression and neuropsychiatric outcome measures, participants with high symptom burden at baseline showed improvement at 1-month postintervention. The intervention had no effect on caregiver burden. Qualitative responses from caregivers described improved engagement for their loved ones, such as laughing more, telling more stories, asking more questions, and having more patience. CONCLUSION The Memory-HEARS intervention is a low-cost, low-risk, nonpharmacologic approach to addressing hearing loss and behavioral symptoms in patients with dementia. Improved communication has the potential to reduce symptom burden and improve quality of life.

Age-related hearing loss in older adults with cognitive impairment

BACKGROUND Hearing loss can impair effective communication between caregivers and individuals with cognitive impairment. However, hearing loss is not often measured or addressed in care plans for these individuals. The aim of this study is to measure the prevalence of hearing loss and the utilization of hearing aids in a sample of individuals with cognitive impairment in a tertiary care memory clinic. METHODS A retrospective review of 133 charts of individuals >50 years who underwent hearing assessment at a tertiary care memory clinic over a 12-month period (June 2014-June 2015) was undertaken. Using descriptive statistics, the prevalence of hearing loss was determined and associations with demographic variables, relevant medical history, cognitive status, and hearing aid utilization were investigated. RESULTS Results indicate that hearing loss is highly prevalent among this sample of cognitively impaired older adults. Sixty percent of the sample had at least a mild hearing loss in the better hearing ear. Among variables examined, age, MMSE, and medical history of diabetes were strongly associated with hearing impairment. Hearing aid utilization increased in concordance with severity of hearing loss, from 9% to 54% of individuals with a mild or moderate/severe hearing loss, respectively. CONCLUSIONS Hearing loss is highly prevalent among older adults with cognitive impairment. Despite high prevalence of hearing loss, hearing aid utilization remains low. Our study highlights the importance of hearing evaluation and rehabilitation as part of the cognitive assessment and care management plan in this vulnerable population.

The Baltimore HEARS Pilot Study: An Affordable, Accessible, Community-Delivered Hearing Care Intervention

Purpose of the Study Age-related hearing loss negatively affects health outcomes, yet disparities in hearing care, such as hearing aid use, exist based on race/ethnicity and socioeconomic position. Recent national efforts highlight reduction of hearing care disparities as a public health imperative. This study a) describes a community engagement approach to addressing disparities, b) reports preliminary outcomes of a novel intervention, and c) discusses implementation processes and potential for wide-scale testing and use. Design and Methods This was a prospective, randomized control pilot, with a 3-month delayed treatment group as a waitlist control, that assessed feasibility, acceptability, and preliminary efficacy of a community-delivered, affordable, and accessible intervention for older adults with hearing loss. Outcomes were assessed at 3 months, comparing immediate and delayed groups, and pooled to compare the cohorts pre- and 3-month post-intervention results. Results All participants completed the study (n = 15). The program was highly acceptable: 93% benefited, 100% would recommend the program, and 67% wanted to serve as future program trainers. At 3 months, the treated group (n = 8) experienced fewer social and emotional effects of hearing loss and fewer depressive symptoms as compared to the delayed treatment group (n = 7). Pooling 3-month post-intervention scores (n = 15), participants reported fewer negative hearing-related effects (effect size = -0.96) and reduced depressive symptoms (effect size = -0.43). Implications The HEARS (Hearing Equality through Accessible Research & Solutions) intervention is feasible, acceptable, low risk, and demonstrates preliminary efficacy. HEARS offers a novel, low-cost, and readily scalable solution to reduce hearing care disparities and highlights how a community-engaged approach to intervention development can address disparities.

Pilot Electroacoustic Analyses of a Sample of Direct-to-Consumer Amplification Products

OBJECTIVE Recent national initiatives from the White House and Institute of Medicine have focused on strategies to increase the accessibility and affordability of hearing loss treatment given the average cost of

A clinic-based intervention to address hearing loss and communication difficulties in patients with dementia and their caregivers

4700 for bilateral hearing aids. More affordable direct-to-consumer hearing technologies are increasingly gaining recognition, but the performance of these devices has been poorly studied. We investigated the technical and electroacoustic capabilities of several direct-to-consumer hearing devices to inform otolaryngologists who may be asked by patients to comment on these devices. PATIENTS/INTERVENTION Nine direct-to-consumer hearing devices ranging in retail cost from