ISBN 9783843957625

978-3-8439-5762-5, Reihe Elektrotechnik

Daniel Fejgin
Exploiting External Microphones for Binaural Direction of Arrival Estimation of Multiple Speakers

192 Seiten, Dissertation Carl von Ossietzky Universität Oldenburg (2026), Hardcover, B5

Zusammenfassung / Abstract

Modern digital hearing aids go beyond basic sound amplification, offering speech enhancement, acoustic scene analysis, and wireless connectivity with other devices. Although several multi-microphone algorithms for hearing aids exist to estimate the direction of arrival (DOA) of speakers in the acoustic scene, their estimation accuracy often degrades in the presence of background noise, reverberation, and multiple simultaneously active speakers. To address this performance degradation, it has been proposed to exploit an additional external microphone (e.g., the microphone of a smartphone) that is spatially separated from the hearing devices and to jointly process all available microphone signals. While such strategies have been shown to improve DOA estimation accuracy, they typically restrict the placement of the external microphone to the vicinity of a speaker, limiting their practicality and real-world applicability.

Motivated by the potential of jointly processing signals from hearing device microphones and external microphones, the primary objective of this thesis is to develop model-based binaural DOA estimation methods for multiple speakers that exploit the availability of an external microphone, without restricting its placement or requiring prior knowledge of its position. The first focus is to develop binaural-only DOA estimation methods for multiple speakers with improved robustness against noise and reverberation. The second focus is to develop strategies for exploiting an external microphone at an unknown position, i.e., not restricted to the vicinity of the speakers, in conjunction with the binaural hearing device setup, and to analyze under which conditions the external microphone provides a benefit.