

3aPP4. Diufhuis pitch and other anomaly pitches.

Jian-Yu Lin

William Morris Hartmann


``Anomaly pitches'' are tonal sensations caused by anomalies in the spectrum of a low-frequency periodic wave, for example, by a missing harmonic [Duifhuis, J. Acoust. Soc. Am. 48, 888 (1970)]. They are immediately heard in the steady state and do not require any reference signal. This paper reports anomaly pitches for both missing harmonics and inverted harmonics. They occur in pulse waves (for any constant phase), in sawtooth waves, in waves with alternating sine and cosine phases, and in waves with Schroeder phase. With a series of missing upper harmonics it is possible to make a virtual anomaly pitch with a missing fundamental. The observations can be compared with the original explanation of the effect by Duifhuis based upon detection of the anomalous harmonic during gaps. Some of the conditions press this explanation to the limit but none has proved fatal. [Research supported by the NIDCD of the NIH.]