Nonsensory factors in infant frequency discrimination

• Published in: Infant behavior & development 1988-04, Vol.11 (2), p.205-222
• Main Authors: Olsho, Lynne Werner, Koch, Elizabeth G., Carter, Elizabeth A.
• Format: Article
• Language: English
• Subjects: auditory perception; Biological and medical sciences; Child development; Developmental psychology; frequency discrimination; Fundamental and applied biological sciences. Psychology; infant audition; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; training effects
• ISSN: 0163-6383; 1879-0453
• DOI: 10.1016/S0163-6383(88)80006-7

Olsho (1984) reported that 5- to 8-month-old infants could discriminate between sounds on the basis of frequency as well as adults at high frequencies, but not at low frequencies. However, both infants and adults in that study performed as well as well-trained listeners at 8000 Hz but more poorly at lower frequencies, suggesting that training factors may have contributed to the difference between infants and adults at low frequencies. This article describes an experiment with naive adult listeners which examined the effects of training on frequency discrimination performance at different frequencies. Naive adults were found to perform as well as well-trained psychoacoustical listeners at 4000 Hz from the very beginning of training. However, their average performance at 500 Hz and 1000 Hz was significantly poorer and more variable than that of well-trained listeners. Four adults continued to practice frequency discrimination for a total of 20 hours. Average performance at 500 Hz and 1000 Hz approached that of trained listeners at the end of training, and variability in performance decreased. Each listener's best performance in each session, however, was close to trained levels at all frequencies even at the beginning of training. Re-analysis of the infant data presented by Olsho indicated that if only the best performance of each listener were considered, the age difference at low frequencies was reduced but not eliminated entirely. This finding suggests that while training factors may contribute to infants' relatively poor low-frequency discrimination, other factors must also be responsible.