RECALIBRATING THE AUDITORY-SYSTEM - THE PERCEPTION OF LOUDNESS

Listening to relatively intense tones at 1 frequency and weak tones at another makes the latter relatively louder. The auditory system's relative response to low-frequency (f1) and high-frequency (f2) tones depends on the separation between f1 and f2. When f1 and f2 differ little, loudness matches change little with shifts in mean sound pressure levels (SPLs) at each frequency; but when f1 and f2 differ more, matches change markedly, showing how the auditory system ''recalibrates'' its responses to f1 and f2. The magnitude of recalibration and its frequency bandwidth also depend to a modest degree on the range of SPLs, their mean level, and the experimental paradigm. The representation of loudness reflects the processing and recalibration of multidimensional peripheral inputs within a higher level, context-sensitive (adaptationlike) mechanism. Other perceptual modalities show evidence of analogous mechanisms.