Twelve new-born infants slept while exposed to 4 sound conditions (no sound; heart
beat; white noise; white noise bursts) in a Latin square design. Observations were
made of the succession of sleep states. White noise and heart beat reduced the period
of time before the onset of regular sleep; the sound conditions influenced the duration
of the regular sleep period. The results show that different sounds have different
effects upon different stages of sleep.
Infant - Sleep state - Sound
