Echo interference creates sinusoidal power fluctuations that average to zero

Evidence

The fluctuations are intrinsic: as long as there are echoes, there will be power fluctuations. This applies to power spectra, which are “point A back to point A” autocorrelations, as well as transfer spectra, which are “point A to point B” cross-correlations. — Eric J. Heller, Why You Hear What You Hear- An…, 1163 (#expands, via linked claim)

Categorization

• XREF: connects to: A returning echo creates power-spectrum peaks spaced by its inverse time — Eric J. Heller, Why You Hear What You Hear- An…, 1096; Any echo-producing system inevitably exhibits frequency power fluctuations — Eric J. Heller, Why You Hear What You Hear- An…, 1163; Power fluctuations persist even where resonances overlap completely — Eric J. Heller, Why You Hear What You Hear- An…, 1154 (+7 more)

Related

• Any echo-producing system inevitably exhibits frequency power fluctuations (similarity 0.93)
• Power fluctuations persist even where resonances overlap completely (similarity 0.85)
• A returning echo creates power-spectrum peaks spaced by its inverse time (similarity 0.85)
• Loudness-time functions reveal echoes and reverberation better than level-time ones (similarity 0.82)
• Power fluctuations persist because echo arrival times unevenly populate Fourier components (similarity 0.81)
• Concert hall power fluctuations are roughly 11 dB regardless of details. (similarity 0.81)
• Throat chamber echoes raise impedance by in-phase amplitude buildup (similarity 0.79)
• Echoes rearrange spectral energy without changing its total (similarity 0.79)
• Fourier analysis of echoes yields alternating strong and weak spectral bands (similarity 0.79)
• Whether echoes constructively add in Fourier analysis depends on wavelength relative to echo timing. (similarity 0.78)
• Early strong versus late weak echoes dictate spectral fluctuation character (similarity 0.78)

Broader Connections

• Any echo-producing system inevitably exhibits frequency power fluctuations #expands (0.95) — Eric J. Heller, Why You Hear What You Hear- An…, 1163
• The power spectrum is blind to the relative phase of a sound’s components #corroborates (0.85)
• Directivity mismatch at crossover frequency causes predictable dips in sound power #exemplifies (0.80)
• Power fluctuations persist even where resonances overlap completely #qualifies (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 1154
• Autocorrelation discriminates echoes from genuine distinct sounds. #contradicts (0.75)
• Interference pattern of correlated sources varies with both listener position and frequency #expands (0.75)
• Throat chamber echoes raise impedance by in-phase amplitude buildup #complicates (0.70) — Eric J. Heller, Why You Hear What You Hear- An…, 544