Induction of spontaneous otoacoustic emissions in chinchillas from carboplatin-induced inner hair cell loss

Fifteen chinchillas were evaluated for spontaneous otoacoustic emissions (SOAEs) before and after administering carboplatin (126-200 mg/kg), an anti-neoplastic drug that selectively destroys inner hair cells (IHCs) in this species. SOAEs were absent from all animals prior to carboplatin treatment, but at 1 week post-treatment, 47% of the animals and 30% of the ears had developed SOAEs. SOAE frequencies were clustered between 5 and 10 kHz and SOAE intensity ranged from 10 to 32 dB SPL. All of the ears with SOAEs had IHC lesions exceeding 60% throughout most of the cochlea and two ears had outer hair cell lesions of 25-60% at a cochlear place associated with the frequency of the SOAE. Thus, high doses of carboplatin that cause IHC loss can be used to create an animal model with SOAEs. (C) 2000 Elsevier Science B.V.