Components of monaural envelope correlation perception

The ability of listeners to discriminate between simultaneously presented bands of noise whose envelopes were either the same or statistically independent was determined. Bands of 100-Hz wide noise were employed which had low and high center frequencies of (2500, 2750), (2500, 3000), (2500, 3500) and (4000, 4400) Hz. Average discriminations were above 90% correct except for the (2500, 3500) Hz condition, which yielded an average of 77% correct. Next, a factorial stimulus design was employed in order to determine the relative importance of envelope and power spectrum cues. The results indicate that in the absence of power spectrum cues, bands with the same envelopes could be discriminated from bands with statistically independent envelopes. When the envelopes were always the same, listeners were able to discriminate between power spectra that were either the same or different. In contrast, when the envelopes were always different, listeners were unable to discriminate between the same and different power spectra.