Audibility Curve of Chinchilla

Abstract

The chinchilla can be readily trained to respond to tones by the method of avoidance conditioning in a shuttle box. In addition, they can be trained for the threshold tests in about the same amount of time as required to train cats. The method for threshold tests is as previously described for cats, with the addition of adding feedback for responses to very weak tones so that the animal knows whether his response was correct. The binaural-audibility curve of chinchilla has been carefully determined at 12-octave steps for six highly trained animals. Below 1000 cps, sensitivity appears to be better than man's; above 2000 cps, it is similar to man's but extends to slightly higher frequencies, that is, about 32 kc/sec. Between 1000 and 2000 cps, chinchillas have narrow regions of low sensitivity; these dips vary in location from animal to animal but are reliable and stable for each.