BackgroundThis systematic literature review is aimed at investigating applications of direct-to-consumer hearing devices for adults with hearing loss. This review discusses three categories of direct-to-consumer hearing devices: 1) personal sound amplification products (PSAPs), 2) direct-mail hearing aids, and 3) over-the-counter (OTC) hearing aids.MethodA literature review was conducted using EBSCOhost and included the databases CINAHL, MEDLINE, and PsycINFO. After applying prior agreed inclusion and exclusion criteria, 13 reports were included in the review.ResultsIncluded studies fell into three domains: 1) electroacoustic characteristics, 2) consumer surveys, and 3) outcome evaluations. Electroacoustic characteristics of these devices vary significantly with some meeting the stringent acoustic criteria used for hearing aids, while others producing dangerous output levels (ie, over 120-dB sound pressure level). Low-end (or low-cost) devices were typically poor in acoustic quality and did not meet gain levels necessary for most adult and elderly hearing loss patterns (eg, presbycusis), especially in high frequencies. Despite direct-mail hearing aids and PSAPs being associated with lower satisfaction when compared to hearing aids purchased through hearing health care professionals, consumer surveys suggest that 5%–19% of people with hearing loss purchase hearing aids through direct-mail or online. Studies on outcome evaluation suggest positive outcomes of OTC devices in the elderly population. Of note, OTC outcomes appear better when a hearing health care professional supports these users.ConclusionWhile some direct-to-consumer hearing devices have the capability to produce adverse effects due to production of dangerously high sound levels and internal noise, the existing literature suggests that there are potential benefits of these devices. Research of direct-to-consumer hearing devices is limited, and current published studies are of weak quality. Much effort is needed to understand the benefits and limitations of such devices on people with hearing loss.

Objective: The current study evaluates the content validity (i.e., domains assessed) and readability levels of patient-reported questionnaire instruments using internationally recognized procedures and tools. Design: A review of the literature to identify candidate instruments and a synthesis of information including mapping extracted items onto the World Health Organization's-International Classification of Functioning, Disability, and Health (WHO-ICF) and estimating readability. Study Sample: 14 patient-reported questionnaire instruments. Results: In general, item content focused on body function and on activity limitations and participation restrictions, with less emphasis on environmental and personal factors, and with different emphases across instruments. Many items did not clearly map onto any of the WHO-ICF categories (i.e., not coded items ranged from 3.7% to 39.1% across the 14 questionnaires). All 14 instruments exceeded the 6 th grade reading level when calculated according to the FORCAST formula which is appropriate for assessing a non-narrative text. Conclusions: Clinical assessment of hearing disability is only as comprehensive as the items covered by the chosen measurement instrument. Our findings confirmed the diversity of domains covered by hearing disability instruments, and gaps in assessment. Some concern is raised about whether the item content is appropriate for those respondents with poor literacy.

ObjectiveContralateral suppression of oto acoustic emission (OAE) is referred as activation of efferent system. Previous literature mentioned about the importance of contralateral suppression of OAEs as a tool to assess efferent system in different groups of population. There is dearth of literature to explore the efferent system function in experienced musicians exposed to rock music using TEOAEs and DPOAEs.MethodsTwo groups of participant (14 rock musicians and 14 non-musicians) in the age range of 18–25 years were involved in the study. Contralateral suppression of TEOAEs and DPOAEs were measured using ILO (Version 6) in both groups.ResultsDescriptive statistics showed higher suppression of TEOAEs and DPOAEs in rock-musicians at most of the frequencies in comparison to non-musicians. For DPOAE measures, Mann Whitney U test results revealed significantly greater DPOAE suppression only at 1 kHz and 3 kHz in rock-musicians compared to non-musicians. For within group comparison, Kruskal Wallis test results revealed there were significant difference observed across most of the frequencies i.e. at 1 kHz, 3 kHz and 6 kHz. For TEOAE measures, Mann Whitney U test results revealed that only at 2 kHz, TEOAE suppression in rock-musician was significantly greater compared to non-musicians. Similarly, Kuskal Wallis test results revealed that within group there were no significant differences observed for most of the frequencies except 2 kHz.ConclusionsBased on the above finding, present study concludes that rock musicians are having better efferent system compared to non-musicians. No suppression effect at few frequencies probably indicates more vulnerability at those frequencies. Contralateral suppression of DPOAE shows more significant finding in comparison to contralateral suppression of TEOAEs in present study.

Most trained musicians are actively involved in rigorous practice from several years to achieve a high level of proficiency. Therefore, musicians are best group to research changes or modification in brain structures and functions across several information processing systems. This study aimed to investigate cortical and subcortical processing of short duration speech stimuli in trained rock musicians and non-musicians. Two groups of participant (experimental and control groups) in the age range of 18-25 years were selected for the study. Experimental group includes 15 rock musicians who had minimum professional training of 5 years of rock music, and each member had to be a regular performer of rock music for at least 15 h a week. Further age-matched 15 participants who were not having any formal training of any music served as non-musicians, in the control group. The speech-evoked ABR (S-ABR) and speech-evoked ALLR (S-LLR) with short duration speech 'synthetic /da/' was elicited in both groups. Different measures were analyzed for S-ABR and S-LLR. For S-ABR, MANOVA revealed significant main effect of groups on latencies of wave V, wave A, and amplitude of wave V/A slope. Similarly, Kruskal-Wallis test showed significantly higher F amplitude in rock musicians compared with non-musicians. For S-LLR, MANOVA showed statistically significant differences observed for latencies of wave P2 and N2 and amplitude measures of P2-N2 amplitude. This study indicated better neural processing of short duration speech stimuli at subcortical as well as cortical level among rock musicians when compared with non-musicians.