Thresholds for tones in maskers of various bandwidths and for signals of various bandwidths as a function of signal frequency.

Critical bandwidth (CB), which represents the narrowest filter the auditory system can achieve, may be estimated directly from either of two experiments. A breakpoint emerges from the threshold function of a pure tone presented with maskers of different bandwidth and from the threshold function of noise signals of different widths masked by wideband noise. The bandwidth at which the knee occurs in either function defines the CB. A "conjoint" CB estimate can also be obtained by extrapolating noise-signal thresholds to be threshold level of a tone in wideband noise. Compared to other estimation procedures, the conjoint estimate is less affected by the signal's spectral splatter, the masker's intensity variability in time, and assumptions about the listening band's placement.