鳥類の音声知覚における時系列および周波数構成要因(音と心理:その多面的な理解をめざして)

抄録

Songbirds learn their song through imitation. Acute auditory perception is required throughout this process. Except for hearing range that is much narrower in birds than in humans, basic hearing abilities in birds and humans are very similar. However, when complex sounds are used, bird and human perceptions are quite different. In this report I compared perception of temporal and spectral factors in humans and birds. I first used operant conditioning techniques to measure discrimination performances on species-specific songs that were played normally and played in reverse order. Birds were more sensitive to the local cues (i.e., direction of frequency modulation) than to the global cues (i.e., the order of the syllables). I also tested whether birds could perceive missing fundamental when spectrally complex sounds were used. Birds not only attended to the missing fundamentals, but also to the average spectra of the stimulus complex.