Introduction
The need for a reliable, simple measure of the dynamics of drug-induced cochlear damage in the laboratory animal is great. Past efforts in this direction have been hampered by cumbersome technique and the statistical requirement of large numbers of test animals, with the result that there is a paucity of precise information on the development of cochlear (as compared to vestibular) damage in animals.1 The over-all result is that man, through serial audiograms, has been the chief source of knowledge about the development of drug-induced hearing loss.There have been some attempts to assess progressive cochlear damage in animals through behavioral observations on pinna twitch or orientation responses to loud sounds.2,3 However, most studies have depended upon end-point examination of the cochlea after a drug schedule has been completed. Histological studies of such material have shown the hair cells to be the site of damage for many