The Potential in Preparing Community Health Workers to Address Hearing Loss.

BACKGROUND: In underserved areas, it is crucial to investigate ways of increasing access to hearing health care. The community health worker (CHW) is a model that has been applied to increase access in various health arenas. This article proposes further investigation into the application of this model to audiology. PURPOSE: To assess the feasibility of training CHWs about hearing loss as a possible approach to increase accessibility of hearing health support services in an underserved area. RESEARCH DESIGN: A specialized three-phase training process for CHWs was developed, implemented, and evaluated by audiologists and public health researchers. The training process included (1) focus groups with CHWs and residents from the community to raise awareness of hearing loss among CHWs and the community; (2) a 3-hr workshop training to introduce basic topics to prepare CHWs to identify signs of hearing loss among community members and use effective communication strategies; and (3) a 24-hr multisession, interactive training >6 weeks for CHWs who would become facilitators of educational and peer-support groups for individuals with hearing loss and family members. STUDY SAMPLE: Twelve Spanish-speaking local CHWs employed by a federally qualified health center participated in a focus group, twelve received the general training, and four individuals with prior experience as health educators received further in-person training as facilitators of peer-education groups on hearing loss and communication. DATA COLLECTION AND ANALYSIS: Data was collected from each step of the three-phase training process. Thematic analysis was completed for the focus group data. Pre- and posttraining assessments and case study discussions were used to analyze results for the general workshop and the in-depth training sessions. RESULTS: CHWs increased their knowledge base and confidence in effective communication strategies and developed skills in facilitating hearing education and peer-support groups. Through case study practice, CHWs demonstrated competencies and applied their learning to specific situations related to effective communication with hearing loss, family support, availability of assistive technology, use of hearing protection, and making referrals for hearing health care. Needs were identified for ongoing training in the area of use of assistive technology and addressing situations of more severe hearing loss and its effects. CONCLUSIONS: Initial results suggest it is feasible to train CHWs to engage community members regarding hearing loss and facilitate culturally relevant peer-health education and peer-support groups for individuals with hearing loss and their family members. In efforts to increase access to audiological services in rural or underserved communities, application of the CHW model with a partnership of audiologists deserves further consideration as a viable approach.

Interventional Audiology to Address Hearing Health Care Disparities: Oyendo Bien Pilot Study.

Interventional audiology, specifically community-based outreach, can connect people with the hearing health care system. Community-based participatory research methods were applied in two phases of research to: (1) investigate the needs of families affected by hearing loss in a rural Arizona community on the U.S.-Mexico border; and (2) evaluate an outreach program on hearing health. The needs assessment included interviews with persons with hearing loss and focus groups with family members and the greater community. The needs assessment revealed that despite perceived severity of hearing loss, help-seeking for audiologic care was limited due to barriers, stigma, and low self-efficacy. Results informed development of a community-based pilot study conducted as part of an academic-community partnership between audiology, public health, and community health workers of a federally qualified health center. An outreach program, Oyendo Bien (hearing wellness), a 5-week, Spanish-language health education program for older adults (n = 21) incorporated communication strategies and behavioral change techniques. Postprogram focus groups revealed increased self-efficacy and decreased stigma. After 1 year, 7 of 9 participants with hearing loss contacted for follow-up had sought some form of hearing-related health care. Future research should further investigate interventional audiology approaches to address health disparities.

The Effects of FM and Hearing Aid Microphone Settings, FM Gain, and Ambient Noise Levels on SNR at the Tympanic Membrane.

BACKGROUND: Speech understanding in noise is challenging for individuals with hearing loss. Hearing aids (HAs) alone are typically unable to resolve these listening difficulties. Frequency modulation (FM) systems or other remote microphone accessories, coupled to HA, are intended to provide listeners with a good signal-to-noise ratio (SNR), thus improving signal audibility and speech understanding. PURPOSE: The goal of this study was to assess variables that influence SNR at the tympanic membrane (TM) when using a remote microphone/HA combination. We examined microphone setting, transmission system gain, and background noise levels using (1) mathematical computations to manipulate variables and observe the outcomes and (2) behavioral testing. RESEARCH DESIGN: This study used mathematical computations to estimate SNR at the TM and a mixed-model experimental design to confirm a subset of the calculations. STUDY SAMPLE: Ten children with normal hearing (mean age, 13.7 yr) and ten adults with high-frequency sensorineural hearing loss (mean age, 49.6 yr) participated. DATA COLLECTION AND ANALYSIS: Speech recognition thresholds were obtained using Bamford-Kowal-Bench sentences in the presence of noise. Participants used an FM system coupled to an HA in an FM-only and an FM + HA microphone condition. RESULTS: Better performance was observed in the FM-only compared to FM + HA condition with the overall amount of the FM-only advantage slightly larger than the mathematical calculations predicted. Further calculations demonstrated that (1) when using an FM-only microphone setting, the SNR at the TM is determined primarily by the SNR at the FM microphone; (2) when both HA and FM microphones are active, the SNR is determined by the highest level of the speech, which is typically at the FM microphone, and the highest level of noise at either the FM or HA microphone; (3) increasing FM gain has no impact on SNR in an FM-only condition; and (4) in an FM + HA condition, increasing FM gain improves SNR. The amount of improvement depends on noise levels at the FM and HA microphones. When the noise levels are similar at the two microphones, an improvement in SNR of ∼2 dB is expected. Greater improvement is expected when the level of the noise at the FM microphone can be reduced relative to the level at the HA microphone. CONCLUSIONS: When using a remote microphone system coupled with a listener's HA, several variables influence SNR at the TM. Two variables that can be manipulated by programming of either or both devices are the microphone setting and gain setting. Mathematical calculations were used to determine the specific influence of and interactions between these variables and showed the importance of (1) managing noise levels to optimize SNR; and (2) counseling clients regarding optimal use of and realistic expectations from their system. This information is useful in the clinical management of persons with hearing loss, especially with the advent and affordability of wireless microphone accessories to assist listeners in background noise.

Modeling the Influence of Acoustic Coupling of Hearing Aids on FM Signal-to-Noise Ratio.

PURPOSE: A model was developed to examine variables that influence signal-to-noise ratio (SNR) at the tympanic membrane (TM) when using a hearing aid (HA) and frequency modulated (FM) system. The model was used to explore how HA coupling influences SNR. METHOD: To generate the model, HA output was measured in a coupler. Known coupler to real-ear transformations and known values for vent (gain) loss as a function of coupling were also used. The model was verified by measuring sound pressure level (SPL) at the TM in 6 ears. RESULTS: The model predicts similar overall SNRs at the TM regardless of coupling method when HA and FM microphones are active. The primary difference in SNR is in the low frequencies and depends on the amount of low frequency insertion gain and the noise levels at the HA and FM microphones. CONCLUSIONS: A model was developed to explore how complex variables contribute to SNR at the TM. One variable, HA coupling, is predicted to have only a minimal effect on SNR at the TM when there is HA gain. Further studies will be needed to assess the real-world effectiveness of an FM system coupled to an open- versus closed-fit HA.

Effects of binaural electronic hearing protectors on localization and response time to sounds in the horizontal plane.

The effects of electronic hearing protector devices (HPDs) on localization and response time (RT) to stimuli were assessed at six locations in the horizontal plane. The stimuli included a firearm loading, telephone ringing and .5-kHz and 4-kHz tonebursts presented during continuous traffic noise. Eight normally hearing adult listeners were evaluated under two conditions: (a) ears unoccluded; (b) ears occluded with one of three amplitude-sensitive sound transmission HPDs. All HPDs were found to affect localization, and performance was dependent on stimuli and location. Response time (RT) was less in the unoccluded condition than for any of the HPD conditions for the broadband stimuli. In the HPD conditions, RT to incorrect responses was significantly less than RT to correct responses for 120 degrees and 240 degrees , the two locations with the greatest number of errors. The RTs to incorrect responses were significantly greater than to correct responses for 60 degrees and 300 degrees , the two locations with the least number of errors. The HPDs assessed in this study did not preserve localization ability under most stimulus conditions.

Effect of presentation modality on immediate and delayed recall in individuals with Alzheimer's disease.

Episodic memory (EM) deficits are the hallmark of Alzheimer's disease (AD). Story-retelling tasks are particularly sensitive to EM impairments and require participants to recall a short story immediately and after a delay. The purpose of this study was to determine whether presentation modality influences story recall in AD participants. Thirty AD participants and 30 healthy elders recalled short stories in (a) auditory, (b) visual, and (c) combined auditory-visual modalities. Recall was assessed immediately as well as after 15- and 30-min delays. Presentation modality significantly influenced story recall in AD participants. AD participants demonstrated better recall after silently reading a story than after hearing an examiner tell the story or simultaneously hearing and reading the story. Clinical implications of these results are discussed.

Effect of release time on preferred gain and speech acoustics.

Eighteen experienced hearing aid users with mild to moderate sensorineural hearing loss were fit with a digital hearing instrument. An adaptive procedure was used to determine their preferred gain setting for continuous speech under six conditions. Release time (RT) was set to 40, 160, or 640 msec. A prerecorded speech stimulus was presented in quiet or in the presence of multitalker babble (10 dB signal-to-babble ratio); all other compression variables were fixed. Real-ear data obtained with settings for each condition suggest that RT did not affect gain preference; however, subjects preferred higher gain in the presence of the multitalker babble. The RMS amplitudes of 30 phonemic units were calculated using ear canal recordings of the speech stimulus for each subject in each condition. Altering RT resulted primarily in decreased amplitude with increased RT, but this effect was not predictable across listeners or conditions.

Interactions of hearing aid compression release time and fitting formula: effects on speech acoustics.

The effects of the interaction of compression release time and prescribed gain on running speech processed through a hearing aid on KEMAR was investigated. A digital instrument was programmed to fit a mild to moderate sloping hearing loss using probe microphone measures to reach targets prescribed by NAL-NL1, DSL I/O, FIG.6 or ASA2p with release times of 40 and 640 ms for each condition. Recordings were made through KEMAR and analyzed to determine the long-term-average-speech spectra, consonant-to-vowel ratios and the RMS amplitude of 32 phonemic units. Aided and unaided results were compared. Within each prescriptive formula, changes in release time affected all of the speech measures subsequent to programming the instrument to a static-composite signal. The short release-time condition produced the greatest alteration to the speech signal. Release time may need consideration when fitting hearing aids to target gain prescriptions.