TDE-ILD-HRTF-Based 3D entire-space sound source localization using only three microphones and source counting

TDE-Based methods are commonly used for wideband sound source localization using at least 4 microphones in 3D space. Using these methods, outdoor (far-field) high accuracy sound source localization in different climates needs highly sensitive and high performance microphones which are very expensive. In the last decade, some papers were published to reduce the microphones count in indoor 2D cases using TDE and ILD-based methods simultaneously. However, using ILD-based methods needs only one dominant source for accurate localization. Also it is known that by using a linear array, two mirror points will be produced simultaneously (half-plane localization). In this paper we try to apply this method to outdoor (low reverberation) cases for a dominant sound source (due to the use of ILD). We propose a novel approach for 3D entire-space localization using TDE, ILD and HRTF simultaneously and only three microphones. Based on the proposed method, a special reflector (instead of dummy head) for microphones arrangement is designed and source counting is used to find that only one dominant sound source is active in the localization area. Simulation results indicate that this approach is useful in outdoor and low degree reverberation cases when source counting and SNR improvement are carried out simultaneously.