Word Discrimination in Cat

Abstract

Ten cats, with one ear surgically destroyed, were trained to discriminate between the spoken words cat and bat. Pure-tone threshold were measured on 6 of these cats. Test trial were presented in which the words were distorted by chopping initial segments of varying durations. Similar tests were conducted with ten human listeners. The shortest chop duration at which discrimination was disrupted was very similar for the cats and the humans. The animals were subjected to intense broad-band noise for different time periods. They were retested on the word discrimination, the reaction to chopped words, and sensitivity to pure tones. Cochlear potentials and eighth-nerve action potentials were recorded and histological sections were made of the cochleas. The effect of the noise trauma on behavior ranged from no effect to apparent total deafness. Results were analyzed in terms of behavioral changes, cochlear physiology, and anatomical destruction of the cochlea.