Localizing Multiple Acoustic Sources With a Single Microphone Array

The ability to localize acoustic sources can greatly improve the perception of smart devices (e.g., a smart speaker like Amazon Alexa). In this work, we study the problem of concurrently localizing multiple acoustic sources with a single smart device. Our proposal called Symphony is the first complete solution to tackle the above problem, including method, theory, and practice. The method stems from the insight that the geometric layout of microphones on the array determines the unique relationship among signals from the same source along the same arriving path. We also establish the theoretical model of Symphony, which reveals the relation between localization performance (resolution and coverage) and impacting factors (sampling rate, array aperture, and array-wall distance). Moreover, the ability to separate and localize multiple sources is also studied theoretically and numerically. We implement Symphony with different types of commercial off-the-shelf microphone arrays and evaluate its performance under different settings. The results show that Symphony has a median localization error of 0.662 m.