People with Bilateral Vestibular Dysfunction (BVD) often experience disabling symptoms, greatly affecting their quality of life and ability to work. Current vestibular treatment does not always allow these patients to fully recover. Many patients either do not improve or reach a plateau with conventional vestibular rehabilitation, and still have difficulty with daily function. The BrainPort™ balance device is intended to provide information about head position to the brain through electrotactile stimulation of the tongue to improve balance in subjects with vestibular disorders.