Abstract - OBJECTIVE: To evaluate the effectiveness of an audio-biofeedback (ABF) system for improving balance in patients with bilateral vestibular loss (BVL). DESIGN: Before-after trial. SETTING: University balance disorders laboratory. PARTICIPANTS: Nine subjects with BVL and 9 unaffected subjects as controls. INTERVENTION: Trunk acceleration ABF while standing on foam with eyes closed. MAIN OUTCOME MEASURE: Balance stability was evaluated according to the following parameters: the root mean square of (1) the center of pressure (COP) displacements and of (2) the trunk accelerations; the COP bandwidth; the time spent by the participant within +/-1 degrees threshold from their baseline COP position; and the mean accelerations of the trunk while the participant was swaying outside this +/-1 degrees threshold. RESULTS: Participants with BVL had significantly larger postural sway than did unaffected participants. Those with BVL, while using ABF, decreased sway area by 23%+/-4.9%, decreased trunk accelerations by 46%+/-9.9%, and increased time spent within +/-1 degrees sway threshold by 195%+/-34.6%. CONCLUSIONS: ABF improved stance stability of participants with BVL by increasing the amount of postural corrections.