Rotating tones and binaural beats as a function of the frequency of the standard signal (f0) and the interaural frequency ratio (f1/f0) were studied in humans. Both beats and rotating tones disappeared as the frequency of the standard signal was increased. The upper limits for rotating tones and binaural beats were estimated at 1170 and 1255 Hz, respectively. Rotating tones were observed with large f1/f0 and were observed almost exclusively with the perception of a single fused image. Binaural beats were obtained with smaller f1/f0 and nonfused images (a separate tone was heard at each ear). Binaural beats and binaural rotating tones may be mutally exclusive phenomenon, with the latter being dependent upon both the binaural capacity to fuse disparate signals and the peripheral auditory system''s capacity to code the temporal information in the signal''s microstructure.