The binaural temporal window in adults and children

Abstract

This study investigated the binaural temporal window in adults and children 5-10.5 years of age. Detection thresholds were estimated for a brief, interaurally out-of-phase (Sπ) 500 Hz pure tone signal masked by bandpass, 100-2000 Hz Gaussian noise. In one set of conditions, the masker was consistently either in phase (No) or out of phase (Nπ). In another set of conditions, the masker changed abruptly in interaural phase (NoNπ or NπNo), and threshold was estimated at a range of delays with respect to the phase transition. Masked thresholds were also obtained in further conditions where the masker interaural phase was steady and the signal was of long duration. Age effects obtained with dynamic maskers could be accounted for by positing that children have a binaural temporal window with a relatively prolonged leading edge or that the children position the binaural temporal window relatively late with respect to the signal. Modeling of the reduced masking-level difference shown by children for a brief Sπ signal presented in a steady No or Nπ masker was more consistent with late placement of a symmetrical binaural temporal window than a binaural temporal window having a relatively prolonged leading edge.

Monaural temporal integration and temporally selective listening in children and adults

“…In contrast, the MLD for the long-duration signal should be relatively adult-like because a delay in temporal weighting of the binaural cues relative to signal onset would not substantially reduce the signal-to-noise ratio with which the long-duration S signal was processed. The results of Hall et al ͑2007͒ were consistent with this hypothesis, indicating that the MLDs of adults and children were not significantly different for the long-duration signal, but that the children had smaller MLDs than the adults for the brief signal ͑due to relatively high NoS thresholds͒.…”

“…Adult data in this and related paradigms ͑e.g., Wightman, 1978, 1979͒ have indicated that the binaural temporal window is substantially longer than the monaural temporal window. The results of Hall et al ͑2007͒ were consistent with an interpretation that the binaural temporal window shape and duration were simi-lar for children and adults, but that children based their performance on a non-optimal weighting of the temporal window output. Children appeared to apply the highest weights to the temporal window output during epochs that were delayed slightly relative to those of adults ͑i.e., children "listened late"͒.…”

“…Results of a recent study reported by Hall et al ͑2007͒ suggested that children did differ from adults in the ability to optimize temporal weighting in the analysis of brief binaural cues ͑i.e., temporally selective listening͒. That study used two paradigms based on the masking level difference ͑MLD͒ ͑Hirsh, 1948͒.…”

“…In the second MLD paradigm employed by Hall et al ͑2007͒, the noise did not have an abrupt interaural phase transition, but instead was either No or N throughout its duration. The signal ͑S͒ was either brief ͑20 ms͒ or long ͑410 ms͒ in duration.…”

The monaural temporal window based on masking period pattern data in school-aged children and adults

“…It could be related to a bias for children to give more weight to information occurring late in the signal presentation (as in Hall et al, 2007) or to maturation in the ability to identify the peak SNR at the output of the temporal window (Hartley et al, 2000).…”