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Yost and Brown (2013, JASA 133) investigated the ability of listeners to localize two simultaneously presented, independent noises presented over loudspeakers from different locations. These experiments demonstrated that SAM noises that were out of phase at two spatially-separated loudspeakers led to better localization performance than when the SAM noises were in phase at each loudspeaker. Performance was improved at SAM rates as high as 200 Hz as compared to non-SAM noise. Yost and Brown hypothesized that listeners' behavior might be explained as a temporal-spectral (T-S) analysis, and showed that such an approach could, qualitatively, account for some of their behavioral data. This presentation will explore the degree to which a quantitative, biologically-inspired peripheral/brainstem auditory model can predict some of the listener performance presented in Yost and Brown 2013. Specifically, the model structure includes simulated auditory nerve response using the Zilany et al. model (JASA, 2014) with rate-count-based estimation of interaural differences of time and intensity as they occur in the presented stimuli recorded with a KEMAR manikin. [ABSTRACT FROM AUTHOR]

In room acoustic scenarios, listeners' localization is often dominated by the sound propagating directly from the its source despite numerous reflections that present different spatial cues only milliseconds later. This is called the precedence effect (PE). Most studies have simulated the PE by presenting one sound (the lead) followed by a copy of the lead that is delayed and presented with different interaural cues (the lag). These simulations assume that reflective surfaces are flat, yet interior surfaces are often far more complex and variable, resulting in spatially and temporally diffuse reflections. The effect of the temporal aspect of this diffusion on listeners' localization of lead/lag, 200-ms duration, noise stimuli filtered to 100-900 Hz and presented over headphones is investigated. Lag stimuli are convolved with a Hanning-windowed 2-ms noise burst to simulate temporal effects of uneven reflective surfaces. Results show that listeners' localization is dominated by the interaural cues of the lead, even when gating onsets/offsets are windowed out. Modeling analyses based on those in Pastore and Braasch 2019 suggest that interaural time differences in the ongoing stimulus portion can be extracted from rising slopes of the envelopes of neural output, even when lead and lag envelopes are decorrelated. [ABSTRACT FROM AUTHOR]

In several recent papers we have shown that listeners perceive differences in the size of a small auditory scene (< 4 sources) for short-duration sounds (e.g., consonant-vowel, CV, pairs) presented at about the same time, but such differences are not perceived for larger scenes. Spatial separation of a small number of sound sources affects performance much more than spatially separating a larger number of sound sources. In this presentation, the number of sound sources is small, but not the number of sounds (CVs). For example, listeners are poor at determining if a target talker is the same as a cue talker, when the target is presented at one sound-source location and several distractor talkers are presented each at different sound-source locations. If all distractor talkers are "clustered (mixed)" at a single source spatially separated from the target sound source, then listeners are better at determining if the target talker was the same as the cue. Several additional scenarios were tested, all indicating that "clustering" sounds into a small number of sound sources improves target-talker identification compared to when sounds are presented from a larger number of sources. [ABSTRACT FROM AUTHOR]

Freeman et al. (J. Exp. Psych.: Hum. Percept. Perform., 2017) demonstrated an auditory analog to the visual Filehne Illusion. For the auditory Filehne Illusion, a stationary sound source is often perceived as rotating in the opposite direction of head rotation, i.e., in a head-centric direction based on the changing auditory-spatial cues due to head rotation. We investigated conditions like the auditory Filehne Illusion for a variety of stimulus and rotation conditions to gain additional insights into how head-position information might compensate for head-centric information (derived from the auditory-spatial cues) to form world-centric, sound-source localization estimates. [ABSTRACT FROM AUTHOR]