Detection of sinusoidally amplitude modulated noise by the chinchilla.
Salvi-RJ; Giraudi-DM; Henderson-D; Hamernik-RP
J Acoust Soc Am 1982 Feb; 71(2):424-429
A study was conducted to compare the amplitude modulation thresholds of the chinchilla with those of man. Four monaural chinchillas were used as subjects. The noise exposure was band limited at either 10 or 20 kilohertz, amplitude modulated at frequencies between 2 and 4096 hertz (Hz) and presented at levels between 52 and 73 decibels (dB) sound pressure level. The modulation thresholds of the chinchilla were about 9 percent at modulation frequencies below 32Hz. At higher modulation frequencies, thresholds increased at the rate of 1.9dB/octave. Modulation thresholds were also measured in human listeners using the same experimental apparatus. Amplitude modulation functions for both subject groups exhibited low pass characteristics. However, the thresholds for humans were better than those of the chinchilla at modulation frequencies below 64Hz. The authors suggest that in order to gain some insight into the mechanisms for coding amplitude modulated sounds, it may be helpful to examine the responses of single units in the auditory periphery of the rat. The authors conclude that the peripheral auditory system may be well suited to coding rapid changes in stimulus amplitude.
NIOSH-Publication; NIOSH-Grant; Noise-induced-hearing-loss; Laboratory-animals; Hearing-loss; Auditory-discrimination
Callier Ctr/communic Disorders Callier Center 1966 Inwood Road Dallas, Tex 75235
Journal of the Acoustical Society of America
University of Texas Dallas, Richardson, Texas