Adults' tolerance of cries: an experimental investigation of acoustic features.
Variations in the aversiveness of a newborn's distress cry were examined using experimental manipulation of 3 acoustic features of the cry (fundamental frequency, intonation, spectral complexity) and of the information given to subjects about the infant's health status. The subjects (N = 164 medical students) were allowed to control the sound pressure level (range: 50 dB [A]-105 dB[A]) of the different cry versions by repeatedly pressing a button (operant titration). For the nonmanipulated (original) cry version, the accepted sound pressure level decreased as fundamental frequency increased at above 610 Hz. This effect was modified by experimental manipulation of spectral complexity as well as intonation. A preference of intonated cries over monotonous cries was most pronounced between 534 and 686 Hz. Significant interactions of the information variable with the intonation and the complexity variables suggest that the listener's reaction to certain physical cry characteristics can be altered substantially by inducing different cognitive sets.