A deaf woman learned to control her excessive vocal loudness through a portable feedback system, which provided vibratory stimulation when her voice was too loud. The mean percentage of excessively loud talking decreased from 45 prior to the use of feedback to 3 during the use of feedback. This improvement (documented by formal observation) was confirmed by normally hearing people sharing the work environment with the woman. The woman preferred a system with a contact microphone since this was virtually unaffected by environmental noise.