[Preference for high frequency sounds of contact calls in primates: Japanese macaques and ringtailed lemurs].

Preference for high frequency sounds in human infants are found by other researchers. The purpose of this study is to examine whether nonhuman primates also have the same tendency as human infants. It is important to consider language origins. Two types of tape recorded coo calls, contact calls, with high and low fundamental frequencies were played back as stimuli for two groups of Japanese macaques (Macaca fuscata). The result showed that the animals of both groups preferred high frequency sounds. To ascertain whether other species also have the same tendency as the Japanese macaques, a playback experiment similar to that for Japanese macaques was conducted for one group of ringtailed lemurs (Lemur catta). Tape recorded mew calls, contact calls, were used as stimuli. The results showed that ringtailed lemurs also preferred high frequency sounds. Moreover, it was clarified by an additional playback experiment for one group of Japanese macaques that animals had an affective preference for high frequency sounds. These results suggest that nonhuman primates have a consistent tendency to prefer high frequency sounds.