critical band

6.24  critical band. (a) For loudness, that frequency band within which the loudness of a band of continuously distributed sound of constant sound pressure level is independent of its bandwidth (see also 6.31); (b) For masking (see C11.31), that frequency band of sound, being part of a continuous-spectrum noise covering a wide band, that contains sound power equal to that of a pure tone centered in the critical band and just audible in the presence of the wideband noise (see C11.32).

Annotation 1      By “just audible” is meant audible in a specified fraction of the trials.

Annotation 2      Use of the critical band to estimate masking should be limited to masking by noises having continuous spectra without excessive slopes or irregularities and to cases where the masking sound pressure level difference exceeds 15 dB.

Annotation 3      Critical band often implies an internal filter through which sound passes in the initial states of auditory processing.

Annotation 4      There are approximately 24 critical bands in the audible range. After Traunmüller [1990], the Critical band rate [in Bark] can be calculated as:

Critical band rate [Bark] = [(26.81f ) / (1960 + f )] – 0.53