Blind Localization of Early Room Reflections with Arbitrary Microphone Array

TL;DR

This paper provides a comprehensive analysis of the FF-PHALCOR method for blind localization of early room reflections with arbitrary microphone arrays, highlighting its performance, limitations, and perceptual benefits.

Contribution

It offers an in-depth evaluation of FF-PHALCOR's effectiveness, proposes improvements, and explores perceptual implications of using estimated reflection data.

Findings

High perceptual quality with 32-microphone spherical array

Reduced quality with 6-microphone semi-circular array

Enhanced detection accuracy and fewer false alarms

Abstract

Blindly estimating the direction of arrival (DoA) of early room reflections without prior knowledge of the room impulse response or source signal is highly valuable in audio signal processing applications. The FF-PHALCOR (Frequency Focusing PHase ALigned CORrelation) method was recently developed for this purpose, extending the original PHALCOR method to work with arbitrary arrays rather than just spherical ones. Previous studies have provided only initial insights into its performance. This study offers a comprehensive analysis of the method's performance and limitations, examining how reflection characteristics such as delay, amplitude, and spatial density affect its effectiveness. The research also proposes improvements to overcome these limitations, enhancing detection quality and reducing false alarms. Additionally, the study examined how spatial perception is affected by generating room impulse responses using estimated reflection information. The findings suggest a perceptual advantage of the proposed approach over the baseline, with particularly high perceptual quality when using the spherical array with 32 microphones. However, the quality is somewhat reduced when using a semi-circular array with only 6 microphones.