Effects of acoustical stimuli delivered through hearing aids on tinnitus

Abstract

Background: The use of acoustic signals to mask, mix with, or ease the distress associated with tinnitus has been clinically employed for decades. It has been proposed that expanding acoustic options for tinnitus sufferers due to personal preferences is desirable. Fractal tones incorporate many useful characteristics of music while avoiding certain features that could be distracting to some individuals.

Purpose: To assess the effects on relaxation, tinnitus annoyance, tinnitus handicap, and tinnitus reaction from the use of a hearing aid that incorporates combinations of amplification, fractal tones, and white noise.

Research design: Participants listened to experimental hearing aids containing several acoustic options and were asked to rate the signals in terms of their effect on relaxation and tinnitus annoyance. They subsequently wore the hearing aids for 6 mo and completed tinnitus handicap and reaction scales.

Study sample: Fourteen hearing-impaired adults with primary complaints of subjective tinnitus.

Intervention: Participants were tested wearing hearing aids containing several programs including amplification only, fractal tones only, and a combination of amplification, noise, and/or fractal tones. The fractal tones (now commercially available as the "Zen" feature) were generated by the Widex Mind hearing aid. Rating procedures were conducted in the laboratory, and tinnitus reaction and handicap were assessed during and following a 6 mo field trial.

Data collection and analysis: Data were collected at the initial visit, one week, 1 mo, 3 mo, and 6 mo. Nonparametric statistics included Wilcoxon matched-pairs signed-rank, chi(2), and repeated-measures analyses of variance.

Results: Thirteen of 14 participants reported that their tinnitus annoyance, as measured by the Tinnitus Annoyance Scale, was reduced for at least one of the amplified conditions (with or without fractal tones or noise), relative to the unaided condition. Nine assigned a lower tinnitus annoyance rating when listening to fractal tones alone versus the amplification-alone condition. There was a range of preferences observed for fractal settings, with most participants preferring fractals with a slow or medium tempo and restricted dynamic range. The majority (86%) indicated that it was easier to relax while listening to fractal signals. Participants had preferences for certain programs and fractal characteristics. Although seven participants rated the noise-only condition as providing the least tinnitus annoyance, only two opted to have noise only as a program during the field trial, and none selected the noise-only condition as the preferred setting. Furthermore, while all four of the experienced hearing aid users selected noise as producing the least annoying tinnitus in the laboratory, only one selected it for field wear. Tinnitus Handicap Inventory and Tinnitus Reaction Questionnaire scores were improved over the course of the 6 mo trial, with clinically significant improvements occurring for over half of the participants on at least one of the measures.

Conclusions: The results suggest that use of acoustic stimuli, particularly fractal tones, delivered though hearing aids can provide amplification while allowing for relief for some tinnitus sufferers. It is important to recognize, however, that tinnitus management procedures need to be supplemented with appropriate counseling.