The effect of noise bandwidth on the auditory arousal response of neonates

Eighteen full-size, full-term, healthy, newborn infants were used in an experiment to determine the relative efficiency of three different noise spectra as audible stimuli. These three signals were high-pass filtered noises with cutoff frequencies of 500, 1000, and 2000 Hz. The metric of efficiency was a very simple count: how many times did an infant display an arousal response to each signal? Each of the three signals was presented eight times to each infant, but the 24 signals were presented in a different random order to each infant. Results showed that neonates are more responsive to wider band signals but are also responsive to lower frequencies. These data are consistent with our earlier findings (also described) and continue to support the use of calibrated wideband signals for auditory screening of newborns.