Binaural Speaker Localization Based on Front/Back-Beamforming and Modulation-Domain Features

Abstract:
In this paper, we propose and evaluate a method for binaural speaker localization using modulation-domain features extracted from the binaural microphone signals of hearing devices. In contrast to most other localization methods the proposed method does not require perfectly synchronized audio signals from the left and the right ear but uses front/back cardioid signals and a classification approach with a small number (< 50) of modulation-domain features for each signal frame. The method employs an efficient implementation of such features using a bank of recursive IIR filters which makes it suitable for low-power portable devices and also allows the application of data-driven optimization procedures. We analyze the capability of these features to reflect not only interaural level differences but also temporal modulation patterns. We evaluate our method on simulated and real-world binaural signals and compare the proposed approach to a beamforming-based method which requires fully-synchronized microphone signals.