Outcomes of Hearing Aid Use by Individuals with Unilateral Sensorineural Hearing Loss (USNHL).

BACKGROUND: Unilateral sensorineural hearing loss (USNHL) can have a negative impact on functions associated with the advantages of balanced, binaural hearing. Although single-sided deafness, which is a complete loss of audibility in one ear, has gained increased interest in the published research, there is a gap in the literature concerning hearing aid outcomes for individuals with residual, or otherwise "aidable," hearing in the affected ear. PURPOSE: To assess hearing aid outcomes for a group of individuals with USNHL with residual, aidable function. RESEARCH DESIGN: A quasi-experimental study of hearing aid outcomes with paired comparisons made between unaided and aided test conditions. STUDY SAMPLE: A convenience sample of twenty-two individuals with USNHL, with sufficient residual hearing in the affected ear as to receive audibility from use of a hearing aid, were recruited into the study from September 2011 to August 2012. INTERVENTION: Each participant was fit with a digital behind-the-ear hearing aid coupled to a custom ear mold. DATA COLLECTION AND ANALYSIS: Assessments were performed at baseline (unaided) and after a three-month field trial (aided) with primary outcomes involving objective measures in sound field yielding signal-to-noise ratio loss (SNR Loss) via the Quick Speech-in-Noise Test and word recognition scores (WRS) via the Northwestern University Auditory Test, No. 6. Outcomes also involved the administration of two well-established subjective benefit questionnaires: The Abbreviated Profile of Hearing Aid Benefit (APHAB) and the 49-item Speech, Spatial, and Qualities of Hearing Scale (SSQ49). RESULTS: As a group, participants showed significantly improved median SNR Loss thresholds when aided in a test condition that included spatial separation of speech and noise, with speech stimuli directed toward the worse ear and noise stimuli directed toward the better ear (diff. = -4.5; p < 0.001). Hearing aid use had a small, though statistically significant, negative impact on median SNR Loss thresholds, when speech and noise stimuli originated from the same 0° azimuth (diff. = 1.0; p = 0.018). This was also evidenced by the median WRS in sound field (diff. = -6.0; p = 0.006), which was lowered from 98% in the unaided state to 92% in the aided state. Results from the SSQ49 showed statistically significant improvement on all subsection means when participants were aided (p < 0.05), whereas results from the APHAB were generally found to be unremarkable between unaided and aided conditions as benefit was essentially equal to the 50th percentile of the normative data. At the close of the study, it was observed that only slightly more than half of all participants chose to continue use of a hearing aid after their participation. CONCLUSIONS: We observed that hearing aid use by individuals with USNHL can improve the SNR Loss associated with the interference of background noise, especially in situations when there is spatial separation of the stimuli and speech is directed toward the affected ear. In addition, hearing aid use by these individuals can provide subjective benefit, as evidenced by the APHAB and SSQ49 subjective benefit questionnaires.

The Benefit of Remote Microphones Using Four Wireless Protocols.

BACKGROUND: Many studies have reported the speech recognition benefits of a personal remote microphone system when used by adult listeners with hearing loss. The advance of wireless technology has allowed for many wireless audio transmission protocols. Some of these protocols interface with commercially available hearing aids. As a result, commercial remote microphone systems use a variety of different protocols for wireless audio transmission. It is not known how these systems compare, with regard to adult speech recognition in noise. PURPOSE: The primary goal of this investigation was to determine the speech recognition benefits of four different commercially available remote microphone systems, each with a different wireless audio transmission protocol. RESEARCH DESIGN: A repeated-measures design was used in this study. STUDY SAMPLE: Sixteen adults, ages 52 to 81 yr, with mild to severe sensorineural hearing loss participated in this study. INTERVENTION: Participants were fit with three different sets of bilateral hearing aids and four commercially available remote microphone systems (FM, 900 MHz, 2.4 GHz, and Bluetooth(®) paired with near-field magnetic induction). DATA COLLECTION AND ANALYSIS: Speech recognition scores were measured by an adaptive version of the Hearing in Noise Test (HINT). The participants were seated both 6 and 12' away from the talker loudspeaker. Participants repeated HINT sentences with and without hearing aids and with four commercially available remote microphone systems in both seated positions with and without contributions from the hearing aid or environmental microphone (24 total conditions). The HINT SNR-50, or the signal-to-noise ratio required for correct repetition of 50% of the sentences, was recorded for all conditions. A one-way repeated measures analysis of variance was used to determine statistical significance of microphone condition. RESULTS: The results of this study revealed that use of the remote microphone systems statistically improved speech recognition in noise relative to unaided and hearing aid-only conditions across all four wireless transmission protocols at 6 and 12' away from the talker. CONCLUSIONS: Participants showed a significant improvement in speech recognition in noise when comparing four remote microphone systems with different wireless transmission methods to hearing aids alone.

The master hearing aid.

As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids.