Effect of signal correlation on the auditory source width in an asymmetricalaly arranged stereo reproduction system

In standard stereo playback systems, the specific wide auditory source width (ASW) can be easily achieved through low correlation between two channels of source signals. However, in practical application scenarios such as car cabins, due to unfavorable factors such as limited acoustic space and non-central listening position, two channels of loudspeakers often cannot be arranged in a standard manner, including the direction and distance, potentially leading to distortions in the listener's perceived ASW. This study analyzes the transformation relationship between inter-channel correlation coefficient (ICCC) of source signals and interaural correlation coefficient (IACC) under asymmetric arrangements by adjusting the asymmetry degree between the listener and the loudspeakers. Then, subjective evaluation of ASW under these conditions is conducted through psychoacoustic experiments. Preliminary experiments indicate that ASW gradually widen as signal correlation decreases from 1. When signal correlation decreases to a certain value, ASW decreases or unnatural auditory events such as sound image splitting and in-head localization occur. The position of the sound image shifts towards the loudspeaker with a larger angle as the asymmetry increases. These results could provide a reference for the optimization and evaluation of stereo signal processing in practical application.