Pitch and timbre in a two-tone dichotic auditory illusion

The Deutsch paradigm that produces an auditory illusion with dichotic alternating 400 and 800 Hz tones [D. Deutsch, J. Acoust, Soc. Am. 55, 518--519, (1974a)] was modified to clarify aspects of pitch and timbre. The 400-Hz sinusoid was replaced by a high-frequency complex tone (1000--1200--1400 Hz) whose residue pitch was perceived as the low stimulus. Significant results based on the response of 21 subjects indicated that the illusion is pitch-, and not frequency-, based. The effect of timbre was found to be negligible.