Perceptual analysis of speech sounds by prelinguistic infants: A first report

Abstract

In this paper we report the results of an investigation that employed a two‐alternative forced‐choice head‐turning paradigm to study speech perception abilities in 5–6‐month‐old infants. Two synthetically produced speech sounds were presented as training stimuli during initial shaping and conditioning phases and the infant was reinforced with the presentation of a visual stimulus (i.e., an animated toy monkey) for an appropriate differential head‐turn response toward the right for one stimulus (S1) or toward the left for another stimulus (S2). Successful discrimination training was followed by a transfer phase in which generalization to a variety of novel speech sounds was measured by observing the direction of the infant's head turns. Implications of our findings and methodology for questions surrounding perceptual constancy, feature analysis and the role of early environmental experience in development of speech perception abilities in young infants will be discussed. [This work was supported by research grants from NIMH and NIH.]