Feasibility and Acceptability of Using Low-Gain Hearing Aids for Bothersome Tinnitus

Overview

Tinnitus - defined as ringing, humming, or other sounds in the ears or head - is a very common problem for Veterans. Hearing aids that deliver low-level amplification are being used by audiologists to help people with tinnitus who also have normal hearing. However, there is a lack of research evidence showing that this practice is effective. Despite this fact, the practice clearly is spreading. Reports from audiologists in the field as well as research presentations refer to hearing aids being used in this way. Use of hearing aids has been shown to reduce distress from tinnitus for people with hearing loss. Additionally, the use of external sound to help reduce the impact of tinnitus has been shown to be effective. There is clearly a gap in the research regarding the use of hearing aids as a therapeutic method to manage tinnitus when hearing is considered normal. This study will obtain pilot data evaluating people with normal hearing and bothersome tinnitus to find out whether low-level amplification through hearing aids may provide benefit.

Tinnitus - defined as ringing, humming, or other sounds in the ears or head - is the most prevalent service-connected disability among Veterans. Tinnitus affects 10-15% of the adult population. For about 20% of these, tinnitus impacts their lives with respect to sleep disturbance, impaired concentration, and/or emotional reactions. These 20% are the most in need of clinical services. It has been shown that providing amplification via hearing aids for people with hearing loss can also be beneficial in reducing functional effects of tinnitus, presumably because amplifying environmental sounds reduces the contrast between the tinnitus and background sound, allowing the tinnitus to be more easily ignored. There have been increasing reports from the field of audiologists providing hearing aids set to deliver low-gain amplification on patients with bothersome tinnitus who are not otherwise hearing aid candidates, with beneficial outcomes. However, this nontraditional fitting practice has not been formally evaluated, so there is no research evidence to support the practice. It is essential for VA to show evidence supporting such practices to justify the use (and expense) of these devices with patients who otherwise do not qualify to receive hearing aids. The proposed project is a pilot study that would lay the groundwork for a future full randomized controlled trial (RCT) evaluating the use of low-gain amplification for bothersome tinnitus in patients with normal hearing. A pilot sample of 20 Veterans with normal hearing thresholds and bothersome tinnitus will be fit with mild amplification through receiver-in-the-canal hearing aids. Hearing aids will be programmed to provide a low-level of amplification, using NAL-NL2 guidelines for target gain. Outcome measures will be evaluated pre-fit and post-fit at two follow-up time points (2 weeks and 3 months post-fit). Outcomes will include the Tinnitus Functional Index (TFI), Hearing Handicap Inventory for Adults (HHIA) and the Quick Speech in Noise (QuickSIN) test. Outcomes pre and post hearing aid fit will be compared to evaluate whether the hearing aids provided benefit to participants in terms of their tinnitus and hearing outcomes. Additionally, participants will be interviewed at their last visit to find out their self-reported benefit from the hearing aids, as well as any barriers they encountered to wearing the hearing aids. Additionally, a group of VA clinical audiologists will be interviewed by telephone. These clinicians will be identified via an email survey sent to the VA audiologist email group, asking whether they are providing low-gain amplification for bothersome tinnitus to patients with normal hearing. The survey will also ask audiologists to volunteer if they are willing to participate in a brief telephone interview. The aim will be to identify at least ten audiologists who are fitting hearing aids in this way, and up to five who are not. These audiologists will be interviewed over the telephone to find out why they have incorporated this into their clinical practice (or why they have not), and inquire about specific fitting procedures and criteria for identifying candidates that they have used. These responses will inform the protocol of the future RCT. At the conclusion of this project, enough information will be collected to propose a controlled study of low-gain amplification for bothersome tinnitus in people with normal hearing. The protocol for that project will be informed by both the successful aspects of the pilot protocol as well as the input from VA clinicians who are doing this in the field. A preliminary evaluation of benefit provided by these hearing aids will provide justification for a large controlled study. Finally, the pilot data will provide the basis for a power calculation to determine sample size, as well as an estimate of drop-out rate to sufficiently adjust for attrition. A full RCT demonstrating efficacy of low-gain amplification for bothersome tinnitus in people with normal hearing would provide needed evidence supporting a clinical practice that has already gained some traction both within and outside VA. Robust research evidence is needed to support the continuation and future expansion of this practice.