Effects of auditory distance cues and reverberation on spatial perception and listening strategies

TL;DR

This study investigates how ecological listening factors—listener movement, reverberation, and source distance—shape spatial localisation. Using an immersive VR setup with spontaneous listening strategies, the authors show that reverberation prompts earlier and larger head rotations and degrades interaural coherence (IACC), while distance improves lateral localisation but does not consistently enhance polar accuracy. The findings reveal that humans adapt listening strategies to acoustic conditions, leveraging head movements to mitigate cue uncertainty, especially under reverberation. These insights have implications for auditory rehabilitation, virtual audio rendering, and the design of hearing devices that must operate under realistic acoustic environments.

Abstract

Spatial hearing, the brain's ability to use auditory cues to identify the origin of sounds, is crucial for everyday listening. While simplified paradigms have advanced the understanding of spatial hearing, their lack of ecological validity limits their applicability to real-life conditions. This study aims to address this gap by investigating the effects of listener movement, reverberation, and distance on localisation accuracy in a more ecologically valid context. Participants performed active localisation tasks with no specific instructions on listening strategy, in either anechoic or reverberant conditions. The results indicate that the head movements were more frequent in reverberant environments, suggesting an adaptive strategy to mitigate uncertainty in binaural cues due to reverberation. While distance did not affect the listening strategy, it influenced the localisation performance. Our outcomes suggest that listening behaviour is adapted depending on the current acoustic conditions to support an effective perception of the space.

Figures (6)

• Figure 1: Experimental paradigm. A) Representation of the used auditory stimulus which is a sum of three components: pink noise, speech and a pure tone; B) Representation of coordinate systems and stimuli locations represented with both, the spherical (in orange) and the interaural coordinate systems. $\theta$ and $\phi$ are respectively the azimuth and elevation, while $\alpha$ and $\beta$ represent the lateral and the the polar angle. For instance, point P is in (90$^\circ$, 45$^\circ$) in the spherical coordinate system and (45$^\circ$, 90$^\circ$) the interaural coordinates. Dots show the tested directions, which are repeated for three different distances (expressed in meters): 0.8, 1.4 and 2.
• Figure 2: Kinematic analysis. Data are presented grouped per reverberation level (Blue: anechoic, Yellow: reverberant) A) (top) Density plot of yaw trajectories (in degrees) over time (in seconds) for each trial and participant, grouped by reverberation level; Dotted lines represent the median trajectory per group computed across trials, participants and target position; (bottom) The t‐test statistic. The critical threshold t$^*$ = 2.471 (red dashed line) is exceeded at time = 1.23s, with a supra‐threshold cluster probability of p=0.03, indicating a significantly higher yaw amplitude angle in the reverberant condition. B) ROM (in degrees) grouped by target distance (in meters) and reverberation level
• Figure 3: Effect of distance-related cues on binaural cues. Binaural cues as a function of target locations (angles in degrees) and reverberation level (blue: anechoic; yellow: reverberant). Shading is relative to the target distance: from brighter (near: 0.5m) to darker (far: 2m). (A) Interaural cross-correlation (B) Interaural Level-difference (in dB) (C) Interaural Time-difference (in $\mu$s)
• Figure 4: Distribution of Localisation errors (in degrees). Lateral precision (A) and accuracy (B) error, Polar precision (C) and accuracy (D) errors grouped for target distance (in meters) and reverberation level (blue: anechoic, reverberant: reverberant). Significance indicators show the outcomes of the repeated measures ANOVA.
• Figure 5: Distribution of quadrant error and effect of motion. A) Quadrant error rate as a function of target distance (in meters) and reverberation level (blue: anechoic, yellow: reverberant). B) Quadrant error rate as a function of ROM (in degrees) and reverberation level (blue: anechoic, yellow: reverberant). Scatter points represent ROM for each subject and each distance. The two lines indicate the fitter regression model. Dashed lines indicate the 95% confidence interval of the linear regression model.