Auditory temporal summation in infants and adults: effects of stimulus bandwidth and masking noise.
A visually reinforced operant procedure was employed to determine the behavioral thresholds of 6- to 7-month-old infants and adults for stimuli of various bandwidths and durations. Experiment 1 compared absolute thresholds for broadband and 1/3-octave filtered clicks and 300-msec noise bursts. For adult subjects, the difference in threshold for clicks and noise bursts was quite comparable in the two bandwidth conditions, but infants' click-noise threshold differences were significantly larger for broadband than for 1/3-octave stimuli. In Experiment 2, 2-point threshold-duration functions were compared for 4-kHz tones and octave-band noise bursts presented in backgrounds of quiet and continuous noise. Infants' threshold-duration function for octave-band noise bursts was significantly steeper than the comparable adult function in quiet, but not in masking noise. These results suggest that young infants may have particular difficulty detecting low-intensity broadband sounds when durations are very short.
Berg
K M
KM
Institute for Advanced Study of the Communication Processes, University of Florida, Gainesville 32611.
D000328:Adult; D001143:Arousal; D001288:Attention; D001309:Auditory Threshold; D003216:Conditioning, Operant; D005260:Female; D006801:Humans; D007223:Infant; D008144:Loudness Perception; D008297:Male; D010470:Perceptual Masking; D010897:Pitch Discrimination; D002666:Psychology, Child