Time-delayed sound self-addition imposes spectral notches via autocorrelation

Evidence

Autocorrelation is a check for repetition or self-similarity. Does the signal, which might look quite unruly, tend in fact to repeat patterns at regular intervals? For example, if there is a large positive fluctuation in s(t) at some time t, does there tend to be another a time τ later? Or, is it anticorrelated at time τ: most often s(t + τ) has the opposite sign as does s(t). The product s(t)s(t + τ) would be most often negative and 〈s(r)s(t + τ)〉 would be negative for that value of the time delay τ. If s(t) and s(t + τ) are uncorrelated, so that s(t)s(t + τ) is as likely positive as negative, the average and thus c(τ) will be zero at time τ. — Eric J. Heller, Why You Hear What You Hear- An…, 369 (#expands, via linked claim)

Categorization

• XREF: connects to: Narrow-band noise self-modulates at 0.64 times its bandwidth — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3336; Time-delayed repetition of sound produces a matching repetition pitch; Delays too short for echoes still audibly alter timbre through spectral combs (+4 more)

Related

• Autocorrelation measures periodic self-similarity in a signal across time delays. (similarity 0.90)
• Autocorrelation discriminates echoes from genuine distinct sounds. (similarity 0.89)
• Time-delayed repetition of sound produces a matching repetition pitch (similarity 0.85)
• A finite-length burst yields a short-lived autocorrelation that vanishes beyond its duration (similarity 0.82)
• Impulse velocity response serves as a ready-made autocorrelation (similarity 0.81)
• Mixing noise with its own delayed copy can create a sense of pitch (similarity 0.80)
• Tiny periodic signals can be recovered from heavy noise via autocorrelation (similarity 0.80)
• Autocorrelation, proposed in 1951, remains essential to pitch perception theory (similarity 0.80)
• Pitch perception corresponds to peaks in the autocorrelation function (similarity 0.79)
• Sub-threshold echoes color sound and can even impart pitch (similarity 0.79)
• Most real sounds have autocorrelations that decay over time. (similarity 0.79)
• Delayed correlated sources produce frequency-dependent comb filtering (similarity 0.79)
• Coincident delayed sounds are far harder to detect than spatially separated ones (similarity 0.79)
• Whether echoes constructively add in Fourier analysis depends on wavelength relative to echo timing. (similarity 0.79)
• Autocorrelation is mathematically equivalent to the power spectrum (similarity 0.78)

Broader Connections

• Delayed correlated sources produce frequency-dependent comb filtering #expands (0.95)
• Delays too short for echoes still audibly alter timbre through spectral combs #expands (0.90)
• Autocorrelation measures periodic self-similarity in a signal across time delays. #expands (0.85) — Eric J. Heller, Why You Hear What You Hear- An…, 369
• Autocorrelation discriminates echoes from genuine distinct sounds. #expands (0.80)
• Mixing noise with its own delayed copy can create a sense of pitch #expands (0.75)