Infants' perception of pitch: Number of harmonics
Journal/Book: Infant Behav Develop. 1996; 19: 355 Chestnut St, Norwood, NJ 07648. Ablex Publ Corp. 191-197.
Abstract: This experiment assessed 7-month-old infants' discrimination of harmonic complexes containing two, three, or five harmonics. In an operant head-turn procedure, infants learned to discriminate between complexes having fundamental frequencies of 160 Hz and 200 Hz. Infants were then presented complexes that contained different-frequency harmonics and were required to categorize them on the basis of their fundamental frequencies. Finally, the fundamental frequency was removed from the sounds, and infants were required to categorize them in accordance with the pitch corresponding to the missing fundamental. Although infants discriminated all the tonal complexes, they successfully categorized only complexes containing three or five harmonics and failed to categorize the two-harmonic complexes, even when they contained the fundamental frequency. These results suggest that infants' perception of pitch deteriorates as the number of harmonics in a tonal complex decreases. Furthermore, infants may need more spectral information to perceive pitch than do adults, many of whom hear the pitch of the missing fundamental for two-harmonic complexes.
Note: Article MG Clarkson, Georgia State Univ, Dept Psychol, Univ Plaza, Atlanta, GA 30303 USA
Keyword(s): auditory perception; pitch perception; missing fundamental; infants; harmonics; COMPLEX TONES; DISCRIMINATION