ORGANIZATION AND DISCRIMINATION OF REPEATING SOUND SEQUENCES BY NEWBORN-INFANTS

A study was conducted to determine whether newborn infants organize au ditory streams in a manner similar to that of adults. A series of thre e experiments investigated the ability of 3- to 4-day-old infants to d iscriminate repeated rising and falling four-tone sequences in two con figurations of source timbre and spatial position. It was hypothesized that if the sequences were organized into two auditory streams on the basis of timbre and spatial position, one of the configurations shoul d be discriminable from its reversal while the other should not. The s equences were tested with different pitch and temporal intervals separ ating the tones. Sequences were discriminated for the first configurat ion by adults at both fast tempo/small interval and slow tempo/large i nterval combinations, while only the latter was discriminated by newbo rns as measured with a non-nutritive high-amplitude sucking paradigm. Neither adults nor infants could discriminate the sequence reversals f or the second configuration. The results suggest that newborn infants organize auditory streams on the basis of source timbre and/or spatial position. They also suggest that newborns have limits in temporal and /or pitch resolution when discriminating tone sequences. (C) 1997 Acou stical Society of America.