Correlation Between Sound Stimulus and Periodicity Pitch

The different possible relations between sound stimulus and periodicity pitch (“Pitch of the Residue”) are investigated quantitatively. The periodicity pitch is measured by adjusting the frequency of a reference pure tone until identical sensation of pitch is achieved. Primarily periodicity pitch is connected with the period of the envelope of the acoustic signal. When changing to a different frequency region of the complex sound (“anharmonic case”), however, the pitch may depart from the envelope frequency up to ±10% even if the envelope period remains unchanged. Furthermore, sound level variations or reduction of noise superimposed on the test signal may cause also variations of the periodicity pitch up to some 2%. A wide frequency shift of harmonic complex tones renders variations of the periodicity pitch in spite of constant envelope period, which amount up to some 2% and are connected with the formation of the periodicity pitch as a subharmonic of the lowest partial of the complex tone. Due to this the periodicity pitch does not exactly coincide with the envelope frequency in the harmonic case either.