Subject: two sine tones simultaneously within one critical band From: Martin Braun <nombraun(at)TELIA.COM> Date: Wed, 5 Oct 2005 16:54:08 +0200Jan Schnupp wrote: > If you play two sine tones simultaneously within one critical band, then > the tones will interfere. Alternating constructive and destructive > interference will cause an amplitude modulation known as "beating". They > will be perceived as a single tone that "warbles" or "flutters" at a > frequency equal to the frequency difference. That's just physics. Physics, yes. But the "beating" effect has nothing to do with the critical band (CB). You hear a "beating", if the two tones are separated by a small frequency difference (up to ca. 15-20 Hz). If the frequency difference is larger than this, the "beating" effect disappears and you hear two tones in dissonance. The border between beating and non-beating is determined by the temporal resolution of the auditory system. This border has no relation to the CB at all. The CB border, for the case of two tones, is the border between consonance and dissonance. Two sine tones are perceived as consonant, if their frequency difference is > CB, and as dissonant, if their frequency difference is < CB. And you hear two tones in both cases. Martin ---------------------------- Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden web site: http://w1.570.telia.com/~u57011259/index.htm