Trials with the Auditory Response Cradle. II--The neonatal respiratory response to an auditory stimulus.

The respiratory response of the neonate to an acoustic stimulus is analysed. It is shown that a response may be indicated by (i) a change in the mean cycle time, (ii) a change in the variability of cycle times, (iii) short or long cycles in the sound-on-period following a regular sequence prior to the stimulus. Responses were found to be independent of the pre-stimulus mean cycle time and variability subject to certain restriction. Decision rules are formulated and applied to the Auditory Response Cradle test results. Good agreement is found between statistical and visual methods of trace analysis.