High‐frequency stimulation in tinnitus treatment

Limited but convincing evidence suggests neural plasticity plays a role in the development and maintenance of tinnitus. Tinnitus is generally pitch matched with high frequencies (<6 kHz) and is often associated with very hearing loss, although the conventional audiometric thresholds may be normal or near normal. It is hypothesized that the brain experiences high‐frequency air conduction auditory deprivation and this is a causative factor in tinnitus. If the low‐pass middle ear is circumvented by bone conduction stimulation, residual high‐frequency receptors in the cochlea can again be activated. High‐frequency bone conduction transducers were fabricated to deliver frequencies from 6 to 40 kHz. The transducers were aluminum ceramic bimorphs with circular topology which were heavily damped by mass loading to the mastoid with resonances at 9 and 39 kHz. Ten subjects with persistent tinnitus were selected to listen to proprietary high‐frequency patterned stimulation for two half‐hour sessions for 4 weeks. Exit questionnaires revealed satisfaction with tinnitus relief in the majority (60%) with residual inhibition lasting on the order of weeks (mean=1.5 weeks). Encouraged by these findings, more extensive trials are underway to explore the efficacy of high‐frequency bone conduction treatment in central tinnitus.