Auditory spatial attention using interaural time differences.

Abstract

Previous probe-signal studies of auditory spatial attention have shown faster responses to sounds at an expected versus an unexpected location, making no distinction between the use of interaural time difference (ITD) cues and interaural-level difference cues. In 5 experiments, performance on a same-different spatial discrimination task was used in place of the reaction time metric, and sounds, presented over headphones, were lateralized only by an ITD. In all experiments, performance was better for signals lateralized on the expected side of the head, supporting the conclusion that ITDs can be used as a basis for covert orienting. The performance advantage generalized to all sounds within the spatial focus and was not dissipated by a trial-by-trial rove in frequency or by a rove in spectral profile. Successful use by the listeners of a cross-modal, centrally positioned visual cue provided evidence for top-down attentional control.

Localization of moving sound

“…This attention-based explanation for the initial forward displacement is compatible with findings indicating that auditory attention oriented to a specific location in space enhances the precision of auditory localization (e.g., Sach, Hill, & Bailey, 2000;Spence & Driver, 1994; for a review, see Scharf, 1998). Also, the results of Experiment 1A can support such an attention-based account: When the visual reference stimulus was visible before the target started, no forward displacement occurred.…”

Masker location uncertainty reveals evidence for suppression of maskers in two-talker contexts

“…One of the ways the auditory system can isolate the talker of interest is to direct attention to the location of that talker. Directing spatial attention to stimuli at a particular location is associated with improved performance for auditory tasks involving both speech (Kidd et al, 2005a;Allen et al, 2009) and non-speech sounds (Rhodes, 1987;Teder and Näätänen, 1994;Mondor and Zatorre, 1995;Teder-Sälejärvi and Hillyard, 1998;Teder-Sälejärvi et al, 1999;Widmann and Schröger, 1999;Sach et al, 2000). In brain imaging studies, there is evidence that the expectation of a stimulus in either the auditory or visual sensory modality increases neural response to the stimulus (Foxe et al, 2005).…”

“…Cuing the location of an auditory stimulus can decrease the response times to non-speech stimuli (Rhodes, 1987;Mondor and Zatorre, 1995;Sach et al, 2000) and improve the comprehension of speech embedded in similar maskers (Kidd et al, 2005a). Studies using recorded event related potentials (ERPs) show stronger responses to non-speech stimuli at attended locations compared to non-attended locations (Rhodes, 1987;Teder and Näätänen, 1994;Mondor and Zatorre, 1995;Teder-Sälejärvi and Hillyard, 1998;Teder-Sälejärvi et al, 1999;Widmann and Schröger, 1999;Sach et al, 2000), consistent with the idea that directed attention increases neural responses to stimuli at expected locations (see also Winkowski and Knudsen, 2006). While these studies all showed that prior knowledge of the location of a target influences performance, less is known about how prior knowledge of masker locations may affect target understanding and SRM.…”

Presentation modality influences behavioral measures of alerting, orienting, and executive control

“…Spatial-orienting benefits have been found with headphone presentation (Bédard et al, 1993;Sach et al, 2000), but the mechanisms by which attention is directed to internal and external sound sources may differ. An alternative approach to investigating auditory orienting is to provide cues to nonspatial features of the auditory signal.…”