This report of a pilot study with 170 unselected neonates considers the effects of signal variables and certain random factors upon auditory behavior. Signal variables differentially affect the incidence of response (response-ratio), the kinds of behavior elicited during response (response-pattern), and the strength of response. Complexity is the prime determinant of response-ratio; response-pattern is affected by frequency and perhaps by duration (below 300 msec). High frequency stimulation elicits behavior which is unique in many ways, and certain aspects of behavior vary systematically with age. All aspects of auditory behavior are modified by activity state, which in turn is systematically altered by repeated stimulation, hunger, and other factors: the response-ratio function resembles adult “cue function” while systematic changes in response-pattern support the “law of initial values” and an “awake-alert-aware” continuum which has been postulated for the ascending reticular formation.

No abstract