Ear and brain adaptation dulls timbre modifications, spurring ever more boost

Evidence

When using equalizers to modify the timbre of a musical sound it is important to be careful to avoid “psychoacoustic fatigue”—this arises because the ear and brain adapt to sounds. This has the effect of dulling the effect of a given timbre modification over a period of time. Therefore one puts in yet more boost, which one adapts to, and so on. The only remedy for this condition is to take a break from listening to that particular sound for a while and then listen to it again later. Note that this effect can happen at normal listening levels and so is different to the temporary threshold shifts that happen at excessive sound levels. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2421

Categorization

• DEFINE: Names and explains ‘psychoacoustic fatigue’ — a core perceptual concept distinct from temporary threshold shift.
• SEED: Article angle: ‘Why You Keep Turning Up the Treble’ — adaptation loops as a lens on tuning, mixing habits, and even emotional desensitization.
• DEEPTHINKING: The adaptation-feedback spiral (boost → adapt → boost more) is a general model of stimulus-seeking that extends well past audio, into attention and consumption.
• XREF: Connects to earlier chapters on auditory adaptation and masking, and to any material on loudness perception and temporary threshold shift. — connects to: Perceptual adaptation to timbre dulls equalizer effects and drives endless compensatory boosts.; Nonlinear distortion generates new frequencies that change timbre with volume; Timbre lacks a one-dimensional subjective scale unlike pitch and loudness — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1425 (+4 more)
• corroborated: 3 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 2421

Broader Connections

• One second of exposure triggers neural spectral adaptation in hearing #exemplifies (0.80) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1252
• Nonlinear distortion generates new frequencies that change timbre with volume #expands (0.78)
• Pipe organ stops can reinforce non-octave harmonics to reshape timbre #exemplifies (0.78)
• Filtering alters timbre, but nearby spectral boosting can partially offset the loss #qualifies (0.75)
• Timbre lacks a one-dimensional subjective scale unlike pitch and loudness #complicates (0.72) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1425
• Timbre reduces to a weighted ratio of fundamental and resolved versus unresolved harmonics #corroborates (0.70)