Transient auditory storage of acoustic details is associated with release of speech from informational masking in reverberant conditions.

Abstract

Perceptual integration of the sound directly emanating from the source with reflections needs both temporal storage and correlation computation of acoustic details. We examined whether the temporal storage is frequency dependent and associated with speech unmasking. In Experiment 1, a break in correlation (BIC) between interaurally correlated wideband or narrowband noises was detectable even when an interaural interval (IAI) was introduced. The longest IAI, which varied markedly across participants, could be up to about 20 ms for wideband noise and decreased as the center frequency was increased for narrowband noises. In Experiment 2, when the interval between target speech and its single-reflection simulation (intertarget interval [ITI]) was reduced from 64 to 0 ms, intelligibility of target speech was markedly improved under speech-masking but not noise-masking conditions. The longest effective ITI correlated with the longest IAI for detecting the BIC only in the low-frequency (<or=400 Hz) narrowband noise. Thus the ability to temporally store fine details contributes to perceptual integration of correlated leading and lagging sounds, which in turn, contributes to releasing speech from informational masking in noisy, reverberant environments.

Effects of age and background noise on processing a mistuned harmonic in an otherwise periodic complex sound

“…However, the N1m and P2m latencies were both longer in older adults. These age-related increases are consistent with prior research (Matilainen et al, 2010;Tremblay et al, 2002) and may reflect a slowing in auditory processing and/or a broadening of the temporal integration window (Emmer et al, 2006;Gleich et al, 2007;Huang et al, 2009), with older adults reaching a saturation in the auditory evoked responses at a longer latency than young adults. An agerelated decline in temporal integration could also account for the reduced ORNm amplitude observed in our prior study (Alain and McDonald, 2007).…”

Perceived target–masker separation unmasks responses of lateral amygdala to the emotionally conditioned target sounds in awake rats

“…The perceived co-location and perceived separation are based on perceptual integration of correlated sound waves delivered from each of the two loudspeakers. It has been confirmed that perceived target-masker spatial separation facilitates the listener's selective attention to target signals and significantly improves recognition of target signals (Freyman et al, 1999;Li et al, 2004;Wu et al, 2005;Rakerd et al, 2006;Huang et al, 2008Huang et al, , 2009. It should be emphasized that when the two loudspeakers are symmetrical to the listener, a change between the perceived co-location and the perceived separation alters neither the target-to-masker ratio in sound pressure level at each ear nor the stimulus-image compactness/diffusiveness (Li et al, 2004).…”

“…What is the role of the precedence effect in noisy, reverberant environments? In a (simulated) reverberant environment, to distinguish signals from various sources and particularly recognize the target source, listeners need to not only perceptually integrate the direct wave with the reflections of the target source (Huang et al, 2008(Huang et al, , 2009) but also to perceptually integrate the direct wave with the reflections of the masking source (Brungart et al, 2005;Rakerd et al, 2006). More specifically, when the delay between a leading sound (such as the direct wave from a sound source) and a correlated lagging sound (such as a reflection of the direct wave) is sufficiently short, attributes of the lagging sound are perceptually captured by the leading sound , causing a single fused sound image as coming from a location near the leading source (the precedence effect, see Wallach et al, 1949;Zurek, 1980;Freyman et al, 1991;Litovsky et al, 1999;Huang et al, 2011).…”

Sensitivity to a break in interaural correlation is co-modulated by intensity level and interaural delay

“…Human listeners are highly sensitive to a temporal break in interaural correlation (BIC, a change of interaural correlation from 1 to 0, then back to 1) (Akeroyd and Summerfield, 1999;Boehnke et al, 2002;Huang et al, 2009a;Huang et al, 2009b;Li et al, 2009). When a BIC occurs at the temporal middle of binaurally presented identical noises, introducing such a drop in interaural correlation does not alter the energy and spectrum but modifies the perceptual compactness/diffuseness, number, placement, and/or loudness of the noise object (Blauert and Lindermann, 1986;Hall et al, 2005).…”