Central deafness: an audiological case study

Cases of central deafness are rare but they can be most informative about the function and dysfunction of the central auditory nervous system. Previous information on the anatomy, physiology, and terminology related to central deafness is reviewed and a patient with central deafness is profiled. The patient suffered bilateral cerebrovascular accidents (CVAs) compromising Heschl's gyrus and some adjacent neural tissue on both sides of the brain. At 18 months post CVAs, this patient could not understand speech presented solely through the auditory modality. Environmental sounds were perceived, but rarely recognized. Pure-tone testing revealed a severe-to-profound hearing loss bilaterally, but otoacoustic emissions, acoustic reflexes, and the auditory brainstem response were essentially within normal ranges for both ears. Middle late and late auditory potentials were compromised, yielding complex modifications of the waveforms. These findings and the compromised vascular anatomy in this case are detailed in this article.