Objective measures of cochlear frequency selectivity in animals and in man. A review

This paper is based on a review lecture presented at the Scientific Workshop on Evoked Potentials at Brugmann University Hospital, Brussels, Belgium on 25 February, 1984. The first part briefly reviews electrophysiological studies in experimental animals which reveal in detail the changes in cochlear function which results from various types of cochlear damage. The experimental animals represent animal models of certain types of sensorineural hearing loss of cochlear origin in man. Particular attention is given to measures of cochlear frequency selectivity and the deterioration which results from cochlear pathology. The second part deals with objective electrophysiological measures of cochlear frequency selectivity (tone on tone suppression curves) in patients with cochlear hearing loss of various etiology. These measures are mainly derived using transtympanic electrocochleography (AP tuning curves); preliminary studies of auditory brainstem response (ABR) P5 tuning curves are also described. Protocols and the rationale for such measures in the clinic are discussed.