Muscle contractions and auditory perception in tinnitus patients and nonclinical subjects.

Evidence has been accumulating linking subjective tinnitus to the somatosensory system. Most subjective tinnitus patients can change the psychoacoustic attributes of their tinnitus with forceful head and neck contractions. This study assessed the significance of such somatic modulation of tinnitus by testing nonclinical subjects. Like tinnitus patients, about 80% of nonclinical subjects, who had ongoing tinnitus at the time of testing (whether or not they were previously aware of it), could modulate their tinnitus with head and neck contractions. Over half of those with no tinnitus at the time of testing could elicit a tinnitus-like auditory perception with head and neck contractions. The finding that forceful head and neck contractions, as well as loud sound exposure, were significantly more likely to modulate ongoing auditory perception in people with tinnitus than in those without tinnitus supports the concept of a neural threshold for tinnitus. Somatic influences upon auditory perception are not limited to tinnitus sufferers but appear to be a fundamental property of the auditory system.