[Perception of music stimuli by the Dichotic Listening Test--studies on college students making a specialty of music].

Nineteen right-handed college students making a specialty of music (9 males and 10 females), were tested in recognition of five kinds of dichotically presented stimuli; originally recorded tones, chords, rhythms, melodies and digits. The tests compared the abilities of each ear to recognize double auditory stimuli presented simultaneously to both ears. As for verbal stimuli, in the recognition of digits stimuli, right ear superiority was found. As for musical stimuli, in the rhythm tests, the mean scores for the right ear were significantly higher than for the left ear. In the melody tests, the right ear superiority was found. In the tone tests and chord tests, the mean scores for the two ears were nearly the same. As for sex differences, no significant differences between males and females in the recognition of five kinds of stimuli. In our last reports, we stated that the primary school and senior high school students belonging to the musical club were tested in the recognition of the same stimuli, and it was suggested that the right hemisphere was superior for melodic recognition and the left hemisphere was superior for rhythmic recognition. Compared with our last reports, it is suggested that there is a difference between musically inexpert individuals and expert ones on the perception of the melodic stimuli. In the early stage of musical training, the melodies are perceived as whole and gestalts and processed in the right hemisphere. By contrast, musically expert individuals perceives the melodies, breaking down tonal sequences and symbolizing. They process melodies in the left hemisphere. It is suggested that the specialization of the music brings the shift of hemispheric lateralization of the perception of melodies.