Prefiltering approaches for time delay estimation in reverberant environments

In recent years much interest has been focused on time delay estimation in reverberant environments, for a variety of practical purposes. Algorithms based on generalized cross correlation are commonly used, but show clear limitations even in the presence of low reverberation levels. More sophisticated approaches, like cepstral prefiltering, have been proposed, but they can be computationally expensive and inadequate for real-time applications. In this paper a novel prefiltering approach, based on the common acoustical pole modeling of room transfer functions, is described and compared to existing techniques. Experimental tests show its effectiveness in combating reverberation while maintaining the simplicity requirement needed in many practical situations.