Auditory Sensitivity Increases in Tinnitus Ears

Details

Published on 25 March 2013

A joint Canadian and French study has concluded that auditory sensitivity is enhanced in tinnitus subjects compared to non-tinnitus subjects, including subjects with normal audiograms.

“Increased auditory sensitivity, also called hyperacusis, is a pervasive complaint of people with tinnitus,” say the authors. “The high prevalence of hyperacusis in tinnitus subjects suggests that both symptoms have a common origin.”
It has been suggested that they may result from a maladjusted increase of central gain attributable to sensory deafferentation. More specifically, tinnitus and hyperacusis could result from an increase of spontaneous and stimulus-induced activity, respectively. One prediction of this hypothesis is that auditory sensitivity should be increased in tinnitus compared with non-tinnitus subjects.
The purpose of the study was to test this prediction by examining the loudness functions in tinnitus ears (n = 124) compared with non-tinnitus human ears (n = 106). Because tinnitus is often accompanied by hearing loss and that hearing loss makes it difficult to disentangle hypersensitivity (hyperacusis) to loudness recruitment, tinnitus and non-tinnitus ears were carefully matched for hearing loss, they reported.

“We interpreted these findings as compatible with a maladaptive central gain in tinnitus,” say the authors.

Source:J Neurosci. 2013 Feb 6;33(6):2356-64.