3-D Sound Source Localization With a Ternary Microphone Array Based on TDOA-ILD Algorithm

Sound source localization is essential for machine-based environmental perception when visual methods are not applicable. Current array-based localization methods often require many microphones and are heavy in computing. This article proposes an efficient algorithm for estimating the location of a single source in 3-D based on the time difference of arrival and interaural level difference (TDOA-ILD) with an array of only three microphones. The algorithm can compute the source 3-D coordinates with a closed-form analytical solution derived from geometrical modeling and identify the actual source from the cone of the confusion area through clustering methods. This article comprehensively evaluates the algorithm’s behavior for various array sizes and source locations in a wide range of signal-to-noise ratios (SNRs) with simulative models to prove that the algorithm achieves estimation errors close to its Cramer–Rao lower bound (CRLB). Experimental evaluation demonstrates the method’s localization feasibility in outdoor open environments with off-the-shelf sensing equipment. The proposed scheme is suitable for real-time 3-D sound source localization with cost-effective hardware.