Tinnitus, the condition that causes constant ringing or buzzing in the ears, has been mysterious for a very long time. Recently, scientists learned that shocking the tongue can reduce its symptoms for a prolonged period of time.
Biomedical engineer Hubert Lim found this by accident. While experimenting with a technique called deep brain stimulation to restore his patient’s hearing, he inserted a rod with several electrodes in five of his patients’ brains. In that process, some of the electrodes landed just outside their target zone (which is not unusual). When the experiment continued, one of the patients, who had tinnitus for a very long time exclaimed, “ oh, my tinnitus! I can’t hear my tinnitus”.
When it comes to tinnitus, the brain is the culprit in many cases, perceiving sounds that are not there, typically caused by misbehaving neurons. To further investigate this, Lim did another experiment with 326 people with tinnitus in which they all sat with a plastic paddle attached to their tongue for up to an hour. The paddle had tiny electrodes that passed electric current to the brain to excite it. The electric stimulation felt like pop rock fizzing in one’s mouth.
The subjects also wore headphones that sent sounds at different frequencies to the brain. The purpose of using both electric stimulation and sound together was to distract the brain by increasing its sensitivity and forcing it to suppress the activity that causes tinnitus in the first place. Over a period of 12 weeks, the subjects who followed the prescribed regimen reported an average drop of 14 points on their tinnitus severity score of 1 to 100. After a follow up with these individuals after one year, they still reported lower tinnitus scores, average drops of 12.7 and 14.5.
Watch the video below to learn more about this study from Hubert Lim. To read the full research paper titled “Bimodal neuromodulation combining sound and tongue stimulation reduces tinnitus symptoms in a large randomized clinical study”, visit the Science Translational Medicine website.