The effect of heartbeat sound stimulation on the weight development of newborn infants.

The weight development of 175 infants was followed from birth to the sixth day after birth. 92 infants were exposed to the sound of an adult's heartbeat 12 hours a day during all 6 days. 83 were not so exposed. No significant difference was found in the weight development of the two groups, thus failing to replicate the previous findings of Salk.