Data on the variation in quiet threshold with stimulus duration for tone pulses have been used to examine the validity of an integration model of the ear's behavior. It is found that the ear responds to short-duration tone pulses in approximately the manner expected of a single time constant integrator, but that there is a significant frequency effect. It is concluded that, within the limits of experimental accuracy, the results can be described either by a reduction in integration time with increasing frequency (from 200 msec at 125 Hz to 100 msec at 10 kHz), or by a constant integration time of 200 msec with a reduction in slope of the integration function as the frequency increases from 125 Hz to 10 kHz.