Auditory rehabilitation after long-term deafness.

Abstract

The duration of preexisting profound deafness in patients with bilateral retrocochlear lesions is known to correlate negatively to the extent of auditory restoration after auditory brainstem implantation. There is, therefore, a lack of information regarding the potential of the central auditory system to mediate hearing perception after long-term deafness. The authors evaluated auditory perception in a case of auditory brainstem implantation after 35 years of deafness. Electrically evoked auditory brainstem potentials could be elicited by both stimulus polarities and were consistent with auditory brainstem origin. Discrimination between temporal and spectral patterns in speech could be achieved. This permitted us to distinguish various voice qualities, especially of familiar speakers in quiet surroundings. The potential of the deafferentiated central auditory system to mediate auditory brainstem implant-induced hearing perception even after very long-term deafness has been demonstrated. Those patients with complete dysfunction of Cranial Nerve VIII for a long period may be considered as candidates for auditory brainstem implantation in the future.