Unfamiliar voice discrimination for short stimuli in newborns

In order to determine the minimal information required for newborns to discriminate unfamiliar voices two experiments were performed using the presentation of single disyllabic words uttered by male and female speakers. In the first experiment, utilizing the standard high-amplitude-sucking procedure, no significant discrimination was obtained. Hypothesizing that his failure in discrimination could be due to a deficient attention at the unique moment of stimulus change, a second experiment was performed in which the same to-be-discriminated stimuli alternated every mimute and in which multiple tokens of the same word were presented to increase stimulus variability. Evidence for voice discrimination was obtained, suggesting that newborns are able to characterize unfamiliar voices on the basis of restrained vocal-tract related information and minor prosodic information. Remarks addressing the consequences of stimulus organization upon attentional demands in experimental procedures in young infants are also presented.