Subjective tinnitus is a sensation of sound without an external source. There is no clear understanding of the cause and pathology of tinnitus.

Literature suggests a combination of deafferentation of the tonotopic map , the Bayesian brain model, and the triple mode network, creating one combined hypothesis for tinnitus pathology. Based on the combined hypothesis, transcutaneous vagus nerve stimulation paired with tinnitus-matched sound stimulation should train the brain to reduce the tinnitus sound's importance, thereby eliminating it from conscious awareness.

To investigate this hypothesis in clinical studies, a device that combines transcutaneous electrical nerve stimulation on the tragus with tinnitus-matched sounds in the ears is needed. The device should be easy to use and electrically safe.

A device has been designed with a user interface that interacts with a microcontroller, following the requirements. The microcontroller controls the audio stimulation shield and the custom-made stimulation circuit designed by Jonathan Kneepkens.

Electrical stimulation of the tragus provides the right effect. It activates the parasympathetic nervous system. The device's efficacy as a treatment must await clinical trials with patient-specific tinnitus-matched acoustical stimulation.