Hearing Aid Self-Adjustment: Effects of Formal Speech-Perception Test and Noise

A Multisite Randomized Controlled Trial Comparing the Effectiveness of Two Self-Fit Methods to the Best-Practices Method of Hearing Aid Fitting

TRIAL DESIGN

This is a randomized multisite noninferiority comparative-effectiveness clinical trial with three parallel branches comparing a best-practices audiologist-fit method to two experimental self-fit (person-fit) methods. Outcomes were measured at 6 weeks and 6 months post-fit.

METHOD

Participants: Five hundred eighty-four participants met the following inclusion criteria and enrolled: (a) age between 50 and 79 years; (b) never used or tried hearing aids previously; (c) can speak, read, and understand English well; (d) willing to purchase the study hearing aids for $650/pair; (e) no diagnosis of a memory or cognitive impairment; (f) 25-item Hearing Handicap Inventory for the Elderly (HHIE) score > 4; (g) Montreal Cognitive Assessment score ≥ 23; and (h) not excluded due to specific audiometric criteria. The audiometric exclusion criteria, based on air-conduction pure-tone thresholds, were as follows: (a) thresholds at all frequencies (250-8000 Hz) < 20 dB HL, for both ears (no hearing loss); (b) pure-tone average for 500, 1000, 2000, and 4000 Hz (PTA4) in the better ear > 50 dB HL (greater than moderate hearing loss); and (c) interaural difference > 20 dB at three or more frequencies or ≥ 40 dB at 500 or 1000 Hz. Interventions: Three groups received the same hearing aids fitted either by an audiologist using best practices (Group AB) or by themselves using one of two efficacious self-fit methods (Groups CD and EF). Objectives: The effectiveness of each of the self-fit methods, CD and EF, was hypothesized to be noninferior to the professional-fit method, AB. Outcomes: The primary outcome measure was the global score from the Profile of Hearing Aid Benefit (PHAB), and the secondary outcome measure was the benefit score (unaided - aided) for the 25-item HHIE. Randomization: Participants were stratified into one of three hearing loss categories based on better-ear PTA4: normal (≤ 20 dB HL), mild (20.1-35 dB HL), or moderate (35.1-50 dB HL). The random assignment of sequential enrollees within each hearing loss category to the three treatment groups made use of a site-specific pregenerated randomization list produced from a random-numbers table. Blinding: It was not possible to blind the participants as to the fitting method used, but the research personnel assessing the outcomes were blinded to the treatment group.

RESULTS

Numbers randomized: The 584 enrollees were randomized to one of the three treatment groups: AB (n = 190), CD (n = 193), and EF (n = 201).

Trial status: The trial began on November 1, 2020, and 6-month outcomes were obtained from the last participant on March 29, 2024. Numbers analyzed: At the 6-week measurement interval, outcome measures were completed for 182 AB, 172 CD, and 178 EF participants, representing 91.1% of the 584 individuals who enrolled. At the 6-month interval, completed outcomes were available for 166 AB, 148 CD, and 151 participants, representing 79.6% of the 584 original enrollees. Outcome: Bootstrapped (N = 1,000) means and 95% confidence intervals (CIs) at 6 weeks were 16.4 (95% CI [14.3, 18.7]), 16.8 (95% CI [14.9, 18.6]), and 15.2 (95% CI [13.5, 17.1]) for the AB, CD, and EF treatment groups on the primary outcome measure (PHAB global). At 6 months, primary outcome scores were 15.5 (95% CI [13.4, 17.8]), 16.3 (95% CI [14.4, 18.2]), and 15.3 (95% CI [13.5, 17.3]) for the AB, CD, and EF treatment groups, respectively. At both measurement intervals, there were no significant effects of treatment group (p > .05) for the primary or secondary outcome measures. Harms: No significant adverse events or side effects were observed.

CONCLUSIONS

At both the 6-week and 6-month postfit intervals, each of the two self-fit methods (CD, EF) yielded outcomes (primary and secondary) that were noninferior to the professional-fit best-practices (AB) fitting method. In addition, on average, clinically meaningful benefit was provided regardless of the fitting method.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28585145.

On the potential benefits of wide dynamic range compression for workers in loud environments: a scoping literature review

This literature review investigates the application of wide dynamic range compression (WDRC) to enhance hearing protection and communication among workers in a noisy environment. Given the prevalence of noise-induced hearing loss, there is a major need to provide workers, with or at risk of hearing loss, with a solution that not only protects their hearing but also facilitates effective communication. WDRC, which amplifies softer sounds while limiting louder sounds, appears a promising approach. This review explores 46 articles investigating WDRC performance on speech intelligibility and loudness perception in noise for individuals with normal hearing or mild to moderate hearing loss. The findings illustrate a complex interplay between several factors such as WDRC parameters, noise types and personal factors. Although WDRC holds promise for enhancing auditory protection and communication in noisy work settings, targeted research towards customizable and adaptive WDRC configurations is crucial for optimizing its application across industrial noise environments.

Behavior Change in Chronic Health: Reviewing What We Know, What Is Happening, and What Is Next for Hearing Loss

Untreated age-related sensorineural hearing loss is challenged by low adoption and adherence to hearing aids for treatment. Hearing care has evolved from traditional clinic-controlled treatment to online consumer-centered hearing care, supported by the increasingly person-centered design of hearing aid technology. Greater evidence and a more nuanced understanding of the personal need for adoption versus adherence to the use of consumer hearing care devices are required. Research considering consumer hearing aid acceptance behavior rests on behavior modification theories to guide clinical approaches to increasing hearing aid adoption and adherence. However, in the context of complex chronic health management, there may be a gap in how these theories effectively align with the needs of consumers. Similarly, market data indicates evolving consumer behavior patterns have implications for hearing care theory and implementation, particularly in terms of sustained behavior change. This essay proposes that evidence, including theory and application, be strengthened by revising basic theoretical premises of personal experience with complex chronic health, in addition to considering recent changes in commercial contexts.

Self-Adjustment of Hearing Aid Amplification for Lower Speech Levels: Independent Ratings, Paired Comparisons, and Speech Recognition

PURPOSE

Self-adjustment of hearing aid amplification enables wearers to customize the hearing aid output to match their preferences and could become an important tool for programming direct-to-consumer devices for people with mild-to-moderate hearing loss. One risk is that user-selected settings may provide inadequate audibility. This study assessed that risk by quantifying relationships between self-adjusted settings, subjective preferences, and speech recognition performance using speech at low levels in quiet, where achieving high speech audibility requires sufficient amplification.

METHOD

Fifteen people with symmetric, mild-to-moderate sensorineural hearing loss self-adjusted hearing aid amplification while listening to speech in quiet at 45, 55, and 65 dBA. After self-adjustment, 11 participants made blinded ratings of their self-adjusted fit, their NAL-NL2 prescriptive fit, and experimenter-created fits with reduced gain. Participants completed blinded paired comparisons and sentence recognition assessments using these settings.

RESULTS

The gain of self-adjusted fits showed a large range of variability between participants. On average, self-adjusted gain was similar to NAL-NL2 prescribed gain for input signals of 55 dBA and slightly greater than prescribed gain for 45-dBA signals. Speech recognition scores for NAL-NL2 fits were consistently high, and differences in speech recognition results were strongly correlated with the overall preferences obtained from paired comparisons.

CONCLUSIONS

Self-adjusted fits are highly variable between individuals for low-audibility conditions. Nonetheless, self-adjusted fits are at least as satisfactory as NAL-NL2 fits, and listeners tend to disfavor settings that result in poorer speech recognition. The findings argue against concerns that self-adjustment will result in inadequate audibility compared to prescribed settings.

Effectiveness of a Self-Fitting Tool for User-Driven Fitting of Hearing Aids

Hearing aids can be effective devices to compensate for age- or non-age-related hearing losses. Their overall adoption in the affected population is still low, especially in underdeveloped countries in the subpopulation experiencing milder hearing loss. One of the major reasons for low adoption is the need for repeated complex fitting by professional audiologists, which is often not completed for various reasons. As a result, self-fitting procedures have been appearing as an alternative. Key open questions with these digital tools are linked to their effectiveness, utilized algorithms, and achievable end-results. A digital self-fitting prototype tool with a novel quick four-step fitting workflow was evaluated in a study on 19 individuals with moderate hearing loss. The tool was evaluated in a double-blinded, randomized study, having two study aims: comparing traditional audiological fitting with the new self-fitting tool, which can also be used as a remote tool. The main reported results show moderately high usability and user satisfaction obtained during self-fitting, and quasi-equivalence of the performance of the classical audiological fitting approach. The digital self-fitting tool enables multiple sessions and easy re-fitting, with the potential to outperform the classical fitting approach.

Open Speech Platform: Democratizing Hearing Aid Research

Hearing aids help overcome the challenges associated with hearing loss, and thus greatly benefit and improve the lives of those living with hearing-impairment. Unfortunately, there is a lack of adoption of hearing aids among those that can benefit from hearing aids. Hearing researchers and audiologists are trying to address this problem through their research. However, the current proprietary hearing aid market makes it difficult for academic researchers to translate their findings into commercial use. In order to abridge this gap and accelerate research in hearing health care, we present the design and implementation of the Open Speech Platform (OSP), which consists of a co-design of open-source hardware and software. The hardware meets the industry standards and enables researchers to conduct experiments in the field. The software is designed with a systematic and modular approach to standardize algorithm implementation and simplify user interface development. We evaluate the performance of OSP regarding both its hardware and software, as well as demonstrate its usefulness via a self-fitting study involving human participants.