The role of auditory feedback in the vocalizations of cats.

The vocalizations of deaf cats were compared with those of littermate hearing controls at 30 days, 50 days, 1 year and 3 years of age. At all ages, deaf cats called more loudly than hearing animals. At 30 days, 50 days, and 3 years, deaf cats called about twice as loudly as hearing animals while at 1 year the calls of the deaf animals were approximately 6 times louder than those of the hearing littermates. Analysis of variance revealed significant differences in call loudness between deaf and hearing animals at 30 days, 1, and 3 years. Deaf and hearing animals did not differ in rate of calling or in the duration of individual vocalizations at 30 days, 50 days, and 1 year. At 3 years, the calls of the deaf animal were shorter than those of the hearing control. The calls of deaf animals were less variable than those of hearing animals at 30 days, 50 days, and 3 years. There was a tendency for the fundamental frequency of the calls of deaf animals to be higher than that of hearing animals at 30 days, 50 days, and 1 year. These results document the importance of auditory feedback in the regulation of feline vocalization.