INFANTS PITCH PERCEPTION - INHARMONIC TONAL COMPLEXES

Two experiments assessed the effects of inharmonicity on 7- to 8-month -old infants' perception of the pitch of tonal complexes. A number of harmonic and inharmonic complexes were presented in a visually reinfor ced operant head turn procedure. In both experiments, infants demonstr ated the ability to discriminate two harmonic complexes based on missi ng fundamental frequencies of 160 and 200 Hz. After learning this basi c task, infants learned to discriminate inharmonic complexes, which we re created by shifting the partials of the harmonic complexes upward b y 30 Hz (experiment 1) br 20 Hz (experiment 2). Finally, three spectra lly different inharmonic complexes represented each pitch, and infants attempted to-categorize those complexes according to their pitches. I n both experiments, infants successfully discriminated the pitches of the spectrally varying tonal complexes, but their performance deterior ated for the more strongly inharmonic complexes of experiment 1. These results suggest that, as for adults, the salience of pitch for inharm onic sounds decreases with increasing inharmonicity. (C) 1995 Acoustic al Society of America.