Mixing noise with its own delayed copy can create a sense of pitch

Evidence

Repetition pitch is perceived (by most but not all listeners) if a non-periodic noisebased signal, for example the sound of a waterfall, the consonants in see, shoe, fee, or a noise generator, is added to a delayed version of itself and played to listeners. When the delay is altered a change in pitch is perceived. — David Howard, Jamie Angus, coustics and Psychoacoustics, 939

Categorization

• SHARE: A fact for the audio-engineer friend: pure noise plus delayed noise yields a pitch — a weird studio trick.
• STORYSTEM: A sound designer’s technique where a delay changes pitch could be the seed of a mystery: a character who can tune water-noise into melody.
• QUESTION: Why do ‘most but not all’ listeners hear repetition pitch? Individual auditory differences worth investigating.
• corroborated: 2 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 939
• XREF: connects to: Time-delayed repetition of sound produces a matching repetition pitch; Time-delayed sound self-addition imposes spectral notches via autocorrelation; A perceived pitch can exist with no partial at its own frequency. (+14 more)

Broader Connections

• Echoed sounds spaced 1-10 ms generate a perceived pitch of 100-1000 Hz #exemplifies (0.90)
• Clear musical pitch arises from regularly repeating acoustic waveforms #expands (0.82)
• Pitch can be perceived even when no partial exists at that frequency #corroborates (0.80) — Eric J. Heller, Why You Hear What You Hear- An…, 2031
• Place and timing theories fail to explain some complex pitch perception phenomena #corroborates (0.78) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 907