Cubic difference tones arise inside the ear, not in the equipment

Evidence

To show that the cubic difference tone is produced in the ear and not somewhere in the technical equipment, you can whistle the constant tone /1 while the rising tone 12 is presented. First only the tone with /1 = 1620 Hz is presented twice and is meant to be a reference for your whistle. Then the rising tone (12 = 1700 Hz to 3000 Hz) is presented. When you whistle along with this rising tone, the decreasing cubic difference tone can be clearly heard, although the two primary tones are produced by different sound sources. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3354

Categorization

• DEFINE: A self-performed whistling experiment proving the cubic difference tone’s site of generation.
• CANDY: You can whistle along with a rising tone and ‘hear’ a third sound that exists only inside your own ear — a party-trick-worthy demo of ear nonlinearity.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3354
• XREF: connects to: Cubic difference tones form from summed wavelets traveling to a characteristic place; The ear generates audible combination tones not present in the stimulus — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1571; Two frequencies can mechanically generate sum and difference frequencies in the ear (+8 more)

Broader Connections

• Two frequencies can mechanically generate sum and difference frequencies in the ear #corroborates (0.92)
• Nonlinear cochlear mechanics make listeners perceive nonexistent difference tones #corroborates (0.88)
• What the ear perceives can diverge from sound’s physical components. #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1568
• Combination tones exist below both source tones and vary in audibility #qualifies (0.78)
• Difference noise generated by ear nonlinearities can be heard before the test tone itself #expands (0.75)
• Combination tones can be objectively measured in the outer ear canal #expands (0.75)
• Upward masking makes intermodulation difference tones more audible than harmonics #expands (0.73) — Toole, Floyd E, Sound reproduction- the acoustics and…, 989
• Zwicker tones arise centrally, not from cochlear mechanics or phase locking #complicates (0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5399