Electroencephalographic decoding of sound location: comparing free-field to headphone-based non-individual head-related transfer functions
Author(s)
Marggraf-Turley, Nils
Shiell, Martha M
Pontoppidan, Niels H
Cappotto, Drew
Picinali, Lorenzo
Type
Journal Article
Abstract
Sound source localization relies on spatial cues, such as interaural time differences, interaural level differences, and monaural spectral cues. Individually measured head-related transfer functions (HRTFs) facilitate precise spatial hearing but are impractical to measure, necessitating non-individual HRTFs, which may compromise localization accuracy and externalization. To further investigate this phenomenon, the neurophysiological differences between free-field and non-individual HRTF listening are explored by decoding sound locations from EEG-derived event-related potentials. Twenty-two participants localized stimuli under both conditions with EEG responses recorded and logistic regression classifiers trained to distinguish sound source locations. Lower cortical response amplitudes were observed for KEMAR compared to free-field, especially in front-central and occipital-parietal regions. ANOVA identified significant main effects of auralization condition and location on decoding accuracy (DA), which was higher in free-field and interaural-cue-dominated locations. DA negatively correlated with front-back confusion rates, linking neural DA to perceptual confusion. These findings demonstrate that headphone-based non-individual HRTFs elicit lower amplitude cortical responses to static, azimuthally varying locations than free-field conditions. The correlation between EEG-based DA and front-back confusion underscores neurophysiological markers' potential for assessing spatial auditory discrimination.
Date Issued
2025-08
Date Acceptance
2025-06-05
Citation
Journal of the Acoustical Society of America, 2025, 158 (2), pp.859-870
ISSN
0001-4966
Publisher
Acoustical Society of America
Start Page
859
End Page
870
Journal / Book Title
Journal of the Acoustical Society of America
Volume
158
Issue
2
Copyright Statement
Copyright © 2025 Acoustical Society of America. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40748294
PII: 3357293
Subjects
Acoustics
Audiology & Speech-Language Pathology
COLLICULUS
CUES
Life Sciences & Biomedicine
LOCALIZATION
MEG
NEURAL RESPONSES
REPRESENTATION
Science & Technology
SPACE
STIMULATION
Technology
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2025-08-01