The Effects of Compensatory Auditory Stimulation and High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Tinnitus Perception - A Randomized Pilot Study.
BACKGROUND
Tinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound.


OBJECTIVE
The purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS).


METHODS
A randomized sham-controlled, single blind study was conducted in a clinical setting on adult participants with chronic tinnitus (n = 14). Compensatory auditory stimulation (CAS) and HD-tDCS were administered either individually or in combination in order to access the effects of both interventions on tinnitus perception. CAS consisted of sound exposure typical to daily living (20-minute sound-track of a TV show), which was adapted with compressive gain to compensate for deficits in each subject's individual audiograms. Minimum masking levels and the visual analog scale were used to assess the strength of the tinnitus percept immediately before and after the treatment intervention.


RESULTS
CAS reduced minimum masking levels, and visual analog scale trended towards improvement. Effects of HD-tDCS could not be resolved with the current sample size.


CONCLUSIONS
The results of this pilot study suggest that providing tailored auditory stimulation with frequency-specific gain and compression may alleviate tinnitus in a clinical population. Further experimentation with longer interventions is warranted in order to optimize effect sizes.
Department of Biomedical Engineering, City College of New York, 160 Convent Avenue, New York, New York 10027, United States of America.
Simon
S
Henin
Department of Biomedical Engineering, City College of New York, 160 Convent Avenue, New York, New York 10027, United States of America.
Dovid
D
Fein
Department of Otolaryngology, Head and Neck Surgery, Mount Sinai Medical Center, New York, NY, United States of America.
Eric
E
Smouha
Department of Biomedical Engineering, City College of New York, 160 Convent Avenue, New York, New York 10027, United States of America.
Lucas C
LC
Parra
D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001307:Auditory Perception / Q000502:physiology*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000706:statistics & numerical data; D010865:Pilot Projects; D016037:Single-Blind Method; D014012:Tinnitus / Q000503:physiopathology / Q000628:therapy*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D064232:Visual Analog Scale