Re-weighting of Sound Localization Cues by Audiovisual Training

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

Detail(s)

Original languageEnglish
Article number1164
Journal / PublicationFrontiers in Neuroscience
Volume13
Online published15 Nov 2019
Publication statusPublished - 2019
Externally publishedYes

Abstract

Sound localization requires the integration in the brain of auditory spatial cues generated by interactions with the external ears, head and body. Perceptual learning studies have shown that the relative weighting of these cues can change in a context-dependent fashion if their relative reliability is altered. One factor that may influence this process is vision, which tends to dominate localization judgments when both modalities are present and induces a recalibration of auditory space if they become misaligned. It is not known, however, whether vision can alter the weighting of individual auditory localization cues. Using virtual acoustic space stimuli, we measured changes in subjects' sound localization biases and binaural localization cue weights after similar to 50 min of training on audiovisual tasks in which visual stimuli were either informative or not about the location of broadband sounds. Four different spatial configurations were used in which we varied the relative reliability of the binaural cues: interaural time differences (ITDs) and frequency-dependent interaural level differences (ILDs). In most subjects and experiments, ILDs were weighted more highly than ITDs before training. When visual cues were spatially uninformative, some subjects showed a reduction in auditory localization bias and the relative weighting of ILDs increased after training with congruent binaural cues. ILDs were also upweighted if they were paired with spatially-congruent visual cues, and the largest group-level improvements in sound localization accuracy occurred when both binaural cues were matched to visual stimuli. These data suggest that binaural cue reweighting reflects baseline differences in the relative weights of ILDs and ITDs, but is also shaped by the availability of congruent visual stimuli. Training subjects with consistently misaligned binaural and visual cues produced the ventriloquism aftereffect, i.e., a corresponding shift in auditory localization bias, without affecting the inter-subject variability in sound localization judgments or their binaural cue weights. Our results show that the relative weighting of different auditory localization cues can be changed by training in ways that depend on their reliability as well as the availability of visual spatial information, with the largest improvements in sound localization likely to result from training with fully congruent audiovisual information.

Research Area(s)

  • auditory-visual perception, sound localization, binaural, head-related transfer function, ventriloquism aftereffect, cue integration, multisensory, behavioral training, INTERAURAL TIME DIFFERENCES, SUPERIOR COLLICULUS, SPECTRAL CUES, DUPLEX THEORY, RECALIBRATION, VENTRILOQUISM, ASYMMETRIES, ADAPTATION, PLASTICITY, EARS

Citation Format(s)

Re-weighting of Sound Localization Cues by Audiovisual Training. / Kumpik, Daniel P.; Campbell, Connor; Schnuppt, Jan W. H.; King, Andrew J.

In: Frontiers in Neuroscience, Vol. 13, 1164, 2019.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal