Pattern recognition within spectrally isolated regions of broadband complex sounds

The iteration of recycled noise segments (RNs) can be heard readily at infratonal repetition frequencies (below 20 Hz,) with “whooshing” (which becomes resolved into components such as “thumps” and “clanks”) heard from 1–4 Hz and “motorboating” (involving a featureless timbre) heard from 4–19 Hz [Guttman and Julesz, J. Acoust. Soc. Am. 35, 610 (1963)]. As previously reported, repetition is heard at all center frequencies when a 1/3‐oct filter is swept through broadband motor‐boating or whooshing RNs. The present study examined the recognition of individual RNs presented first with limited spectral bandwidths, and then embedded in broadband “parents.” Accurate performance required bandwidths greater than a critical band and center frequencies less than 4.8 kHz. These results, and those from a second experiment involving identification of narrow‐band derivatives of previously heard broadband RNs, will be discussed in terms of (1) the relative contribution of different spectral regions to recognition of long‐period waveforms and (2) the ability to perceptually segregate broadband patterns into discrete spectral regions. [Work supported by AFOSR and NIH.]