Stimulating the tongue with electricity reduces tinnitus

A Dublin-based biotech company developed a device that reduces the severity of tinnitus by applying an electrical current to the patient's tongue. Neuromod Devices' simulator includes a set of headphones that emit tones in various frequencies and an iPod-like unit that delivers an electrical current through a lollipop- like paddle that the patient puts in their mouth. The stimulation is described as feeling like "pop rocks or a fizzy soda."

From IEEE Spectrum:

Some tinnitus cases are caused by actual sounds generated in the ear, such as changes in blood vessels so that a person is literally hearing the blood pumping in their head. These can often be surgically treated. But most cases are caused by altered brain wiring. These cases are often associated with hearing loss and thought to be the result of the brain overcompensating for that loss, leading to hyperactivity and abnormal brain activity patterns, like revving a car engine that you're afraid is about to stall.   

While testing brain implants to treat deafness more than a decade ago, [Hubert Lim, chief scientific officer of Neuromod and an associate professor of biomedical engineering and otolaryngology at the University of Minnesota] noticed that stimulating somatosensory regions of the brain—that is, areas associated with the perception of touch, pressure, temperature, and pain—caused a decrease in tinnitus in patients. When starting his own lab in Minnesota in 2009, Lim began testing different ways to activate somatosensory pathways without a brain implant, by stimulating the ears, neck, limbs, tongue and more.