Offsetting siren hole rows shifts perceived pitch by changing periodicity

Evidence

Now, using the phase tool, offset one row of holes by 6 degrees (0.016666 x 2π radians; type 0.016666 in the box). This setting causes the second set of 30 holes to sound exactly halfway between those of the first set, making a 300 Hz periodicity with the disk revolving at 5 Hz. The 6-degree offset setting is equivalent to 60 evenly spaced holes in the same row. — Eric J. Heller, Why You Hear What You Hear- An…, 2102

Categorization

• XREF: Connects to the missing fundamental and periodicity-pitch literature — how pitch derives from temporal repetition rather than spectral content. — connects to: Periodicity in the acoustic waveform determines whether a sound is perceived as pitched. — David Howard, Jamie Angus, coustics and Psychoacoustics, 828