The discrimination of speech and nonspeech stimuli in early infancy

Abstract

The discrimination of synthetic speech and nonspeech stimuli was investigated in infants 40–54 days of age by means of a nonnutritive conjugate sucking procedure. Four groups of Ss were given repeated presentations of one auditory stimulus, and upon habituating to it, were shifted to a second (postshift) stimulus. For Group P (Place) the pre- and postshift stimuli differed according to place of articulation {[ba−] vs [ga−]}. Group I (Intonation) received a stimulus shift consisting of a difference in intonation {[ba−] vs [ba+], i.e., falling vs rising intonation}. Group C (Control) was presented with the same stimulus during preshift and postshift {[ba−]}. For Group NS (nonspeech control) the pre- and postshift stimuli consisted of the isolated acoustic cues which differentiate the place stimuli [ba] and [ga]. Changes in hi-amplitude sucking revealed that infants 40–54 days of age can discriminate the acoustic cues for place of articulation and intonation. Furthermore, a comparison of the place and nonspeech control conditions suggested that infants respond to the acoustic cues for place in a linguistically relevant manner.