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
