Present paper deals with the problems of predicting temporary threshold shift (TTS) produced by intermittent noises of which off time is longer than two minutes. In the first experiment, to obtain the growth and recovery of TTS at 4 kc, three subjects with normal hearing acuity were exposed to 2000∼4000 cps octaveband noises at 90 db for durations from one minute to 35 minutes. (Figs.2 and 3) In the second experiment, six types of intermittent exposure to 2000∼4000 cpc noises 90 db shown in Fig.4 were used. TTS2 (TTS two minutes after cessation of each exposure), residual TTS (TTS that exists just before the beginning of re-exposure) and TTS in recovery process after the intermittent exposure were measured on the same three subjects. The results of these experiments revealed that 1) the exposure-equivalent rule proposed by Ward etal. was valid in expeirmental conditions containing various off-times from four to 10 minutes, 2) TTS following the intermittent exposure could be predicted based on the exposure-equivalent rule and the equations of recovery process of TTS, and 3) recovery of TTS produced by the repeated exposure proceeded slightly slower than that of TTS produced by the continuous exposure.