A Mixed-Methods Trial of Broad Band Noise and Nature Sounds for Tinnitus Therapy: Group and Individual Responses Modeled under the Adaptation Level Theory of Tinnitus

Abstract

Objectives: A randomized cross-over trial in 18 participants tested the hypothesis that nature sounds, with unpredictable temporal characteristics and high valence would yield greater improvement in tinnitus than constant, emotionally neutral broadband noise.Study Design: The primary outcome measure was the Tinnitus Functional Index (TFI). Secondary measures were: loudness and annoyance ratings, loudness level matches, minimum masking levels, positive and negative emotionality, attention reaction and discrimination time, anxiety, depression and stress. Each sound was administered using MP3 players with earbuds for 8 continuous weeks, with a 3 week wash-out period before crossing over to the other treatment sound. Measurements were undertaken for each arm at sound fitting, 4 and 8 weeks after administration. Qualitative interviews were conducted at each of these appointments.Results: From a baseline TFI score of 41.3, sound therapy resulted in TFI scores at 8 weeks of 35.6; broadband noise resulted in significantly greater reduction (8.2 points) after 8 weeks of sound therapy use than nature sounds (3.2 points). The positive effect of sound on tinnitus was supported by secondary outcome measures of tinnitus, emotion, attention, and psychological state, but not interviews. Tinnitus loudness level match was higher for BBN at 8 weeks; while there was little change in loudness level matches for nature sounds. There was no change in minimum masking levels following sound therapy administration. Self-reported preference for one sound over another did not correlate with changes in tinnitus.Conclusions: Modeled under an adaptation level theory framework of tinnitus perception, the results indicate that the introduction of broadband noise shifts internal adaptation level weighting away from the tinnitus signal, reducing tinnitus magnitude. Nature sounds may modify the affective components of tinnitus via a secondary, residual pathway, but this appears to be less important for sound effectiveness. The different rates of adaptation to broadband noise and nature sound by the auditory system may explain the different tinnitus loudness level matches. In addition to group effects there also appears to be a great deal of individual variation. A sound therapy framework based on adaptation level theory is proposed that accounts for individual variation in preference and response to sound.Clinical Trial Registration: www.anzctr.org.au, identifier #12616000742471.

A comparison of the severity of tinnitus in patients with and without hearing loss using the tinnitus functional index (TFI)

“…However, there were no significant differences in; severity of cognition (x 2 =4.71, p=0.095), and however that the TFI is a subjective measure of tinnitus severity self-reported by individual patients. There is evidence to show that it differs from tinnitus severity determined using other methods, such as psychoacoustic measurements and several other studies have shown that THI scores did not correlate significantly with tinnitus loudness measurements (Zhao et al, 2019;Durai and Searchfield, 2017).…”

A State-of-the-Art Review: Personalization of Tinnitus Sound Therapy

“…We believe that a contributing factor to the inconsistent benefit reported with sound therapies (Mckenna and Irwin, 2008 ; Hobson et al, 2012 ) is application of a single title “sound therapy” to a very heterogeneous collection of different sound-based approaches. In addition individual needs and reaction to therapy sounds differ (Durai and Searchfield, 2017 ) we ascribe to the philosophy that individuals are most likely to manage their tinnitus better when the treatment plan is tailored to their needs (Fisher and Boswell, 2016 ).…”

A randomized single-blind controlled trial of a prototype digital polytherapeutic for tinnitus

“…Methods to measure individual characteristics and goals have been developed (23,24). Feasibility, proofof-concept and small randomized trials have investigated potential components of a polytherapeutic including counseling (25) passive sound therapy (26)(27)(28)(29)(30) and active training (31)(32)(33). From this work a prototype smartphone-based digital therapeutic was developed to provide therapy focused on providing relief, relaxation, and attention focused retraining (34) within the context of counseling focusing on Attention, Reaction, Explanation, and Adaptation [AREA (25)].…”