A new hearing test applicable to the crying newborn infant.
Hearing tests in newborn infants hitherto described have been designed to elicit a response to a sound when the infants are quiet or asleep. It has been accepted that there was no response when they were crying. The present observation describes the effect of a sound stimulus on the crying newborn infant. I have observed that if the infant is not extremely distressed it is possible to get a response regularly. What I did was to make a continuous sound at a distance of 15 to 30 cms. and the babies regularly stopped their cry sequence. The vocal intensity required was less than that of the baby's cry. This quieting response suggests auditory attention or a reflex mediated at a cortical level. The response to this vocal sound is analysed in terms of its effect on heart rate and respiration. It is compared with the effect of a pure tone stimulus of different pitch. It seems to be elicited with notes of low pitch and occurs independent of age or birth weight. The implications and possible long-term significance of the response will be discusses.
D000161:Acoustic Stimulation; D001143:Arousal; D001288:Attention; D003448:Crying; D006311:Hearing Disorders / Q000175:diagnosis*; D006320:Hearing Tests / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn