Estimation of Interaural Time Differences Based on Zero-Crossings in Noisy Multisource Environments

This paper presents a new method for estimating interaural time differences (ITDs) in noisy multisource environments. To estimate ITDs, conventional methods use cross-correlation of left and right instantaneous firing rates of neurons. However, these methods require high computational complexity involved in the computation of cross-correlation. Furthermore, they suffer from inaccuracies in estimating ITDs, especially in noisy multisource environments. In this context, we propose a new method using zero-crossing time differences (ZCTDs) detected from binaural filter-bank outputs in which a distinctive feature is to estimate the signal-to-noise ratios (SNRs) of filtered signals using the variances of ITD estimates. As a result, the proposed ZCTD method with SNR estimation is able to provide an accurate estimate of multiple sound source directions and is more robust to noise while offering significantly less computational complexity compared to the conventional cross-correlation based methods