A comparison of chinchilla auditory evoked response and behavioral response thresholds

The auditory sensitivity of the chinchilla was measured by both a behavioral and auditory evoked-response (AER) procedure. There was no significant difference in either the waveform or the threshold of the AER recorded over the tentorium from awake and anesthetized chinchillas. The chinchilla threshold for pure tones appears to be more sensitive when measured by the behavioral technique than by the AER method. Both the AER and behavioral response of three chinchillas exposed to a 105 dB SPL octave band of noise centered at 2 KHz for 3 h shifted markedly after the exposure. However, the difference between the AER and behavioral response threshold was reduced or absent. During the process of recovery the difference between the two responses begins to reappear.