Pattern specificity in the effect of prior Δƒ on auditory stream segregation.

Abstract

During repeating sequences of low (A) and high (B) tones, perception of two separate streams ("streaming") increases with greater frequency separation (Δƒ) between the A and B tones; in contrast, a prior context with large Δƒ results in less streaming during a subsequent test pattern. The purpose of the present study was to investigate what aspects of the context pattern are necessary for this context effect to occur. Simply changing the B-tone frequency without an alternating A tone present was not sufficient to cause the effect of prior Δƒ, but rather a melodic change between A and B tones was necessary. We further investigated the extent to which the context and test patterns needed to have similar rhythms (xxx-xxx-) and melodies (up-down-flat-up-down), and found that a maximal prior-Δƒ effect occurred when the rhythmic patterns of the context and test were similar, regardless of the melodic structure. Thus, the effect of prior Δƒ on streaming depended on the presence of (1) at least one melodic change in the context, and (2) similar rhythmic patterns in the context and test.

Loss and persistence of implicit memory for sound: Evidence from auditory stream segregation context effects

“…Specifically, these studies have consistently found that listeners are more likely to report perceiving a test sequence as two separate streams when the preceding (or context) sequence contained a small Δƒ than when the context sequence contained a large Δƒ Snyder et al, 2008;Snyder, Holder, et al, 2009;Snyder & Weintraub, 2011). In addition to this contrastive effect of prior stimulation, a facilitative effect of prior judgment was also found, whereby listeners were more likely to report perceiving the test sequence as two separate streams if they had also reported perceiving the context sequence as two streams than if they had reported perceiving the context sequence as a single stream Snyder et al, 2008;Snyder, Holder et al, 2009).…”

“…It was also recently shown that the Δƒ of the previously presented sequence(s) and whether the listener perceived the previous sequence(s) as one stream or two have a major impact on subsequent perceptual judgments Snyder et al, 2008;Snyder, Holder, et al, 2009;Snyder & Weintraub, 2011). Specifically, these studies have consistently found that listeners are more likely to report perceiving a test sequence as two separate streams when the preceding (or context) sequence contained a small Δƒ than when the context sequence contained a large Δƒ Snyder et al, 2008;Snyder, Holder, et al, 2009;Snyder & Weintraub, 2011).…”

“…In the present study, we utilized recently discovered context effects in auditory scene analysis tasks (Snyder, Carter, Hannon, & Alain, 2009;Snyder, Carter, Lee, Hannon, & Alain, 2008;Snyder, Holder, Weintraub, Carter, & Alain, 2009;Snyder & Weintraub, 2011; see also Riecke, Mendelsohn, Schreiner, & Formisano, 2009;Riecke et al, 2011) to determine the extent to which implicit memories consist of memories that are lost versus persistent. Context effects in stream segregation have been demonstrated using sequences of tones organized into a repeating triplet pattern, ABA-ABA-.…”

“…Instead, this may result from a type of perceptual priming found in visual studies (for a review, see Pearson & Brascamp, 2008; see the General Discussion section for more details). Alternatively, a framework based on adjustments to perceptual judgment criteria might be able to account for both the contrastive nature of the prior Δƒ effect and the facilitative nature of the prior perception effect (Treisman & Williams, 1984; for an in-depth discussion, see Snyder & Weintraub, 2011).…”

The effects of rhythm and melody on auditory stream segregation

“…Recently, Bendixen et al Bendixen et al, 2010) showed that the auditory system can utilize regular temporal patterns for sorting sounds into streams (see also Andreou et al, 2011;Rimmele et al, 2012;Snyder and Weintraub, 2011). However, while the regularities tested by Bendixen and colleagues Bendixen et al, 2010) extended the intervals during which listeners perceived the tone sequence in terms of two streams, they did not affect the length of the intervals during which listeners perceived the tone sequence as a single integrated stream.…”