The siren showed sinusoid partials arise without any sinusoidally vibrating source

Evidence

In figure 3.11, the smaller fork is vibrating faster than the larger fork by factor of exactly 3/2. Using f1 = 200 and f2 = 300, the displacement of the smaller tines reads … Notice that it is perfectly periodic. Its frequency is 100 Hz, lower than either the 200 Hz or the 300 Hz component. The two waves return to their starting phase at the same time after three periods of the 300 Hz wave and two periods of the 200 Hz wave; this time is 0.01 second, corresponding to a frequency of 100 Hz. Here is the first hint of a crucial issue, one that extends to theories of music and hearing. If any single pitch can be associated with this combination, it is certainly 100 Hz, but there is no 100 Hz frequency present at all. One can also easily “hear out,” as it is called, the 200 and 300 Hz “atomic” components as individual sinusoidal pure tones embedded in the “molecular” whole. There is much more evidence to present regarding pitch perception, and we leave this subject for a full discussion in chapter 23. — Eric J. Heller, Why You Hear What You Hear- An…, 323 (#expands, via linked claim)

Categorization

• XREF: connects to: Phantom tones are heard despite being absent from the presented sound; Horn confinement amplifies siren output via proximity resonance.; A combined waveform can produce a perceived pitch absent from its actual frequency components — Eric J. Heller, Why You Hear What You Hear- An…, 323 (+2 more)

Related

• A combined waveform can produce a perceived pitch absent from its actual frequency components (similarity 0.87)
• A perceived pitch can exist with no partial at its own frequency. (similarity 0.84)
• Non-sinusoidal sources still produce audible sinusoidal partials. (similarity 0.84)
• A bell’s perceived pitch is usually absent from its actual partials (similarity 0.84)
• Even nonperiodic noise sounds convey a weak pitch sensation based on spectral energy distribution (similarity 0.83)
• Phantom tones are heard despite being absent from the presented sound (similarity 0.83)
• The ear perceives a virtual pitch not physically present in a sound’s components (similarity 0.82)
• A short pop can still carry a recognizable resonant pitch (similarity 0.82)
• Pitch can exist with no tone heard at that frequency, unlike phantom tones (similarity 0.81)
• A sound can rise in pitch forever without ever rising in frequency (similarity 0.81)
• Combination tones exist below both source tones and vary in audibility (similarity 0.80)
• Rotating siren holes changes partial phase but also alters shared partial amplitude. (similarity 0.80)
• Sinusoidal vibration is the fundamental atom of all sound (similarity 0.80)
• Nonlinear vibration generates new frequencies absent from the original stimulus (similarity 0.80)
• A pitch can be heard even when only its higher harmonics are present (similarity 0.80)

Broader Connections

• Nonlinear vibration generates new frequencies absent from the original stimulus #expands (0.85)
• Phantom tones are heard despite being absent from the presented sound #expands (0.82)
• A combined waveform can produce a perceived pitch absent from its actual frequency components #expands (0.82) — Eric J. Heller, Why You Hear What You Hear- An…, 323
• Horn confinement amplifies siren output via proximity resonance. #expands (0.78)
• Humans hear spectral content, not waveform shape or phase shifts #expands (0.75) — , Toole, Floyd E - Sound reproduction-…, 504