A PRACTICAL TIME-DELAY ESTIMATOR FOR LOCALIZING SPEECH SOURCES WITH A MICROPHONE ARRAY

A frequency-domain-based delay estimator is described, designed specifically for speech signals in a microphone-array environment. It is shown to be capable of obtaining precision delay estimates,over a wide range of signal-to-noise ratio conditions and is computationally simple enough to make it practical for real-time systems. A location algorithm based upon the delay estimator is then developed. With this algorithm it is possible to localize talker positions to a region only a few centimetres in diameter (not very different from the size of the source), and to track a moving source. Experimental results using data from a real 16-element array are presented to indicate the true performance of the algorithms.