Apparently the pitch difference limen (DL) for a single high‐frequency sinusoid can be smaller in the presence of a nearby constant frequency component than in isolation. It is demonstrated that this effect arises from the time‐envelope properties of the two‐frequency complex. This result is consonant with those of Flanagan and Saslow who found that the pitch DL of a periodic vowel sound is smaller than the DL of a sinusoid at the fundamental frequency.