Lateralization thresholds based on differences in interaural arrival time have been measured for jittered 4-kHz tones. The results are in good agreement with those of other authors obtained with bandpass noise as well as with AM and FM signals. However, thresholds are about two orders of magnitude higher than those of Nordmark [J. Acoust. Soc. Am. 60, 870–880 (1976)] obtained with jittered tones. These results suggest an explanation of the lateralization of jittered tones and other FM signals on the basis of an hypothesized FM-to-AM conversion which may take place peripherally.