Auditory potentials in profoundly deaf subjects

In 12 healthy volunteers, and 5 prelingually and 5 postlingually profoundly deaf subjects, a 500 Hz filtered click stimulus was applied to the mastoid via the bone conductor. In all the healthy volunteers, middle latency response (MLR) was recorded. Among all profoundly deaf subjects, MLR was recorded only in 2 with prelingually deafness; these two subjects were also the only ones with normal vestibular function. The possible mechanisms of the MLR appearance in deaf subjects are discussed.