This study is a prospective, multi-center, randomized double-blinded study comparing the postural stability of BVD subjects using the BrainPort™ balance device to postural stability of control subjects using a sham device and respective baseline measures for each group. The primary objective of this study is to determine whether electrotactile stimulation of the tongue, using the BrainPort™ balance device, can improve postural stability, as measured by improvement in performance of the composite Computerized Dynamic Posturography using the NeuroCom® Sensory Organization Test in subjects with chronic bilateral vestibular dysfunction (BVD). The secondary objectives are to evaluate improvement in quality of life, as measured by the Activities Specific Balance Confidence (ABC) Scale, Dizziness Handicap Inventory (DHI), and the Dynamic Gait Index (DGI), and to demonstrate a decreased number of falls on the NeuroCom® Sensory Organization Test. In addition, we will monitor the number of falls that occur during subjects' normal activities of daily living. The long-term objective is to evaluate the safety and efficacy when the device is used over a one-year period.