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 (Spi) 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 (Npi). In another set of conditions, the masker changed abruptly in interaural phase (NoNpi or NpiNo), 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 Spi signal presented in a steady No or Npi masker was more consistent with late placement of a symmetrical binaural temporal window than a binaural temporal window having a relatively prolonged leading edge.