Age-related changes in temporal resolution: Envelope and intensity effects

Gap-detection thresholds were determined for 10 younger and 10 older adults at two sensation levels (40 and 60 dB SL) for tone pips with Gaussian ampl itude envelopes whose standard deviations were 0.5, 1, 1.5, and 2 ms. Gap-d etection thresholds were larger for the older participants under all condit ions. For all participants, gap-detection thresholds increased with the sta ndard deviation of the Gaussian amplitude envelope, were relatively indepen dent of sensation level, and were independent of the degree of hearing loss . Because spectral splatter decreases with increasing standard deviation of the Gaussian amplitude envelope, the age-related differences in gap-detect ion cannot be attributed to differences between how young and old listeners are affected by off-frequency cues. Furthermore, the consistent age differ ence in gap-detection at all amplitude envelope standard deviations was sho wn to be incompatible with the hypothesis that temporal integration time is longer for older listeners.