Organizational processes in infants' perception of auditory patterns.

Infants 9-11 months of age were tested for their discrimination of changes in the melodic contour (direction of successive pitch changes) of brief melodies in the context of discernible variations in key (different absolute frequencies, same intervals) or interval size (different absolute frequencies and frequency ratios, same contour). Infants detected contour changes in both variable contexts, suggesting that they categorize sequences of sounds on the basis of global, relational properties such as melodic contour. Implications of such processing strategies for infants' perception of running speech are considered.