The ear and brain adapt to sounds, dulling perceived changes over time.

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. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2421

Categorization

• DEFINE: Introduces ‘psychoacoustic fatigue’ as a named concept distinct from threshold shift.