Residual inhibition.

Following offset of an appropriate masking stimulus, tinnitus may remain suppressed for a period, typically less than a minute. This phenomenon is known as "residual inhibition" (RI). This chapter reviews the psychoacoustic properties of RI and their relation to hearing impairment, tinnitus spectra, and the spectra of masking stimuli. RI is also contrasted with tinnitus suppression produced by repetitive transcranial magnetic stimulation (rTMS) the cortical effects of which do not require the ear to reach the brain. Although the two procedures act in different ways, both may reduce tinnitus by interrupting abnormal synchronous activity among networks of neurons that generate tinnitus. Therapies that induce tinnitus suppression by these methods have been reported to reduce tinnitus distress by processes that are not well understood.