Perceptual dimensions of listener envelopment (LEV) in a positional and directional-varying context

The Listener Envelopment (LEV) is, along with the Apparent Source Width (ASW), an essential perceptual attribute of auditory Spatial Impression. The perception of LEV was extensively studied across concert halls. It is however unclear how this perception varies when measured across different positions and head orientations. In this paper, an investigation is conducted to reveal how LEV and its sub-dimensions vary across four different positions in a reverberant concert hall. At each position, three different head orientations were assessed. The relationships between the perceptual variations and objective measures such as the late lateral sound strength (LG₈₀) and left-to-right energy ratios (LRR) are investigated and finally, perceptual models based on the objective measures are proposed. Results suggest that the Apparent Reverb Width (ARW) and the Perceived Reverb Loudness (PRL) can accurately describe two different sub-dimensions of Listener Envelopment (LEV). It was also suggested that measures of late-lateral energy ratio and lateral sound strength may be more accurate descriptors of perceptual envelopment, as opposed to decorrelation measures such as IACC_L3, which do not vary greatly across the different positions measured in this study. It is believed that a better understanding of the perceptual variations in listener envelopment will be useful for more efficient and accurate rendering of virtual acoustics in a 6-degree-of-freedom VR/AR/XR scenario, where the listener can freely move across an entire virtual space.