[Fetal perception and discrimination of speech stimuli; demonstration by cardiac reactivity; preliminary results]

Human fetuses (35-38 ws GA), exposed to a repeated pair of syllables, either [ba] [bi] or [bi] [ba], at 95 dB SPL when in a low heart rate variability state, display a significant heart rate deceleration. Changing the order of the syllables in the pair, [ba] [bi] becoming [bi] [ba] (or the reverse), induces a new cardiac deceleration. This suggests that fetuses demonstrate auditory discrimination abilities for speech units like syllables.