The impact of reference tones on the adjustment of interaural cues

Abstract

In the time-intensity trading paradigm, trading ratios are inconsistent in that they differ as a function of which cue is to be adjusted by the listener. Two explanations have been offered: First, the regression model assumes a regression to the interaural parameters of a reference tone played in alternation with the test tone to cause the phenomenon of inconsistent trading ratios. The second explanation is based on an inflated perceptual weighting of the to-be-adjusted cue. The perceptual-weight explanation has been supported by experimental results showing that the phenomenon of inconsistent trading ratios appears even in the absence of a reference tone. Those findings render regression as the sole explanation for inconsistent trading ratios implausible. The experiments presented in this paper address the question whether regression to the parameters of a reference tone plays a role if a reference tone is presented. Three experiments were conducted in which trials with and without reference tone were compared directly. Both within- and between-subject comparisons showed that a reference tone affects trading ratios and location judgments if present. Although regression cannot be the sole explanation for the phenomenon of inconsistent trading ratios it seems to play a role if a reference tone is presented.

Context-dependent trading of binaural spatial cues in virtual reality

“…The physical presence of a midline reference tone would lead to an even greater displacement of the percept from midline, because the repeated reference tone would become the adaptor. This scenario could account for the same pattern of results demonstrated by Ignaz et al, (2014) (i.e., greater shift-back effect in the presence of a reference tone).…”

“…Consistent with the variety of factors at play in determining the frequency selectivity of binaural cues discussed above, multiple parameters affect ITD/ILD equivalence relations: the cue being adjusted (Young Jr & Levine, 1977); task (Lang & Buchner, 2008); adaptation (Thurlow & Jack, 1973); cue magnitude (David Jr et al, 1959); feedback (Carlile et al, 2001); the distance of the cues from the listener (Shinn-Cunningham et al, 2000); interclick interval (Stecker, 2010); relative laterality between cues (Moushegian & Jeffress, 1959); naturalness (Gaik, 1993); masking (Teas, 1962); and whether a reference tone is present (Ignaz et al, 2014).…”

“…While subsequent work has accounted for several behavioral phenomena in violation of the duplex theory, the relationship between interaural differences in time and level have yet to be fully understood. For instance, the seemingly straightforward question of determining the ITD required to offset an opposing ILD has yielded a variety of results that depend on a number of factors (e.g., David Jr et al, 1959;Hafter & Carrier, 1972;Ignaz et al, 2014;McFadden et al, 1972;Young Jr & Levine, 1977). The discrepancies in perceived azimuth when directly setting one binaural cue against the other represents a fundamental unexplained phenomenon in the processing of binaural cues for spatial hearing, and is the focus of the current study.…”

“…In an effort to determine whether regression or upweighting acted alone or in concert to influence trading relations, Ignaz et al (2014) measured equivalence relations both with and without the presence of a reference tone in the same participants. They found that while cuespecific trading relations occurred in the absence of a reference tone, confirming the experiments of Buchner (2008, 2009), the shift-back effect was greater when a reference was presented in alternation with the target, in support of the regression hypothesis.…”

“…Thus, the main conclusion to be drawn between the TRs of these two studies is further confirmation that broadband stimuli provide larger TRs than pure tones. Lang and Buchner (2009), as well as studies in the same vein (Ignaz et al, 2013(Ignaz et al, , 2014Lang & Buchner, 2008), have also used the MOCS in the context of cue trading; however, the MOCS task stimuli consist solely of the chosen cue values used to center the stimuli during an MOA task. That is, after centering a stimulus using the MOA, these authors then presented listeners with single presentations of the cue values that were judged at midline in a MOCS task.…”