Assisted RTF-Vector-Based Binaural Direction of Arrival Estimation Exploiting a Calibrated External Microphone Array

TL;DR

This paper introduces a method for binaural DOA estimation that leverages a calibrated external microphone array to improve accuracy in reverberant environments, outperforming previous approaches without such assistance.

Contribution

It proposes a novel approach using a calibrated external microphone array to enhance RTF-vector-based DOA estimation in binaural hearing aids.

Findings

Assisted method outperforms non-assisted in reverberant environments.

Utilizes a second database of calibrated RTF vectors for improved accuracy.

Constructs a 2D spatial spectrum for precise DOA estimation.

Abstract

Recently, a relative transfer function (RTF)-vector-based method has been proposed to estimate the direction of arrival (DOA) of a target speaker for a binaural hearing aid setup, assuming the availability of external microphones. This method exploits the external microphones to estimate the RTF vector corresponding to the binaural hearing aid and constructs a one-dimensional spatial spectrum by comparing the estimated RTF vector against a database of anechoic prototype RTF vectors for several directions. In this paper we assume the availability of a calibrated array of external microphones, which is characterized by a second database of anechoic prototype RTF vectors. We propose a method, where the external microphones are not only exploited to estimate the RTF vector corresponding to the binaural hearing aid but also assist in estimating the DOA of the target speaker. Based on the estimated RTF vector for all microphones and both prototype databases, a two-dimensional spatial spectrum is constructed from which the DOA is estimated. Experimental results for a reverberant environment with diffuse-like noise show that assisted DOA estimation outperforms DOA estimation where the prototype database characterizing the array of external microphones is not used.