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Demo · Auditory perception

Residue Pitch

the missing fundamental, demonstrated · entry 535 · entry 536

A harmonic series at 200, 300, 400, 500, 600 Hz implies a fundamental at 100 Hz. Remove the 100 Hz component entirely — the pitch doesn't change. The auditory system reads the harmonics as testimony to a generator that isn't there and produces a pitch response to the implied source. This is residue pitch: the pitch you hear when the fundamental is absent.

Toggle harmonics below to add or remove them. The "Telephone" preset removes all components below 300 Hz, matching the telephone band-pass filter — the fundamental disappears from the spectrum but the pitch of a male voice survives. The implied pitch is always 100 Hz as long as any harmonics of 100 Hz remain present.

Controls
Harmonics — click to toggle
Frequency content
0 Hz200 Hz400 Hz600 Hz800 Hz900 Hz
Press play to begin.