Narayana Murthy BHVS(Research Centre Imarat), Satyanarayana J.V.(Research Centre Imarat), Nivedita Chennupati(International Institute of Information Technology Hyderabad) and Bayya Yegnanarayana(International Institute of Information Technology at Hyderabad)
This paper presents a method of obtaining the instantaneous time delay of broadband signals collected at two spatially separated microphones in a live room. The method is based on using the complex signals at the output of single frequency filtering (SFF) of the microphone signals. We show that the complex SFF spectrum at each instant can be used to obtain the instantaneous time delay (TD). By using only the phase of the SFF spectrum, it is possible to get a better estimate of the TD, as in the case of the standard GCC-PHAT method. We show the effectiveness of the proposed method for real microphone signals collected in a live room. Robustness of the method is tested for additive babble noise at 0 dB for the live microphone data. Since we get the TD at every sampling instant, it may be possible to exploit this feature for two-channel multi-speaker separation and for tracking a moving speaker.