Auditory sensitivity was tested in three monaural chinchillas using standard techniques and the auditory-evoked potential technique (AEP). Hearing was measured at octave steps from 500 to 8000 Hz before, 1 day after, and 30 days after exposure to a simultaneous combination of 50 impulses (A duration = 30 microseconds) presented at a rate of of 1/min and at 158 dB pe SPL and continuous noise (1 h of 95 dB 2-4 kHz octave band of noise). The two independent assessments of auditory sensitivity showed good agreement and the results support the use of AEP testing in experimental animals.