Phase changes become audible in three-tone complexes

Evidence

Phase differences become audible if the spectrum consists of three tones. Variation of phases may also be detected by a change in rhythm, a sensation discussed in Chap. 13. Only data of just-noticeable phase differences are discussed here, and sounds composed of three tones of equal frequency separation will be used. In this case, changes in phase can produce a change from amplitude modulation to quasi-frequency modulation. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1081