Rhythm perception can arise from pitch variation alone without loudness change

Evidence

Whereas most rhythmic events can be detected by means of variations in the (specific) loudness-time functions, variations in pitch can sometimes lead to rhythmic events despite constant loudness. In such cases, the variations in pitch have to be calculated according to the models of spectral pitch or virtual pitch described in Chap. 5. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1519