Enhancement of time delay estimation in reverberant environments by signal prefiltering

Spatial diversity is an important issue in many practical applications, such as acoustic source localization, audio signal enhancement, speech recognition in the presence of interference. In particular, source localization by time delay estimation and triangulation represents a popular class o approaches. In this work, the basic time delay estimation technique via the generalized crosscorrelation function and an improved version using cepstral analysis are briefly reviewed. Then a novel approach is proposed, which exploits the physics of sound propagation in closed environments. Specifically, the common acoustical mode approximation of room transfer functions is udes to devise a simple and effective prefiltering technique. Finally, the performance of all proposed solutions is compared at different reverberation levels.