Differential sensitivity of newborns to synthetic vowel stimuli

Three-day-old babies were presented with synthetic speech stimuli and some no-sound trials. Three factors of the speech stimuli were examined: vowel quality change, pitch (F0) change, and stimulus presentation rate. The motor behaviour of the neonates was assessed using a multi-response observation method. The babies responded more when the vowel quality changed than when it did not. In some conditions, pitch variation and stimulus presentation rate also affected d'. The work extends previous findings on newborn auditory sensitivity showing differential responding to steady state vowels and that alterations in F0 can affect behaviour. The method has advantages in permitting several stimuli to be compared as well as studying neonates in states of arousal typical of perinatal experience.