Analysis of room reverberation effects in source localization using small microphone arrays

Small microphone arrays provide many advantages for real-world audio applications. Together with digital signal processing, their enhanced acoustic properties can be exploited in many speech processing systems, such as hands-free devices, videoconferencing or hearing aids. Among their classical applications is source localization, which is usually based on the estimation of Time-Differences-Of-Arrival (TDOA). The accuracy of these methods depends on the degree of reverberation, due to the increased variance found in TDOA estimates. In this paper, we characterize reverberation in a room by means of a small three-microphone array. Our experiments show that the directional distribution of time-frequency estimates is highly correlated with the room´s reverberation. This correlation results in a model that can be very useful for both estimating reverberation time and setting the resolution achievable in source localization tasks.