Use of local kurtosis measure for spotting usable speech segments in co-channel speech

A novel method to process co-channel speech was proposed by Krishnamachari, Yantorno, Benincasa and Wenndt (see ICSPACS, 2000). Previous methods include enhancing the target speech, or suppressing the interfering speech or both enhancing the target and suppressing the interferer. The proposed new method searches for usable speech frames which are usually found in clusters under co-channel conditions. The term "usability" is context dependent, i.e., usable in the context of such things as speaker identification, gisting, etc. We investigate the use of kurtosis for spotting usable speech segments under co-channel conditions. Preliminary results reveal that a kurtosis of 1.5 or greater occurs close to the beginning and ends of segments of usable speech, i.e., they usually bracket the usable speech segment. For the male/male case, we observe that 92% of usable clusters are spotted, for the male/female case 83% of usable clusters are spotted and for the female/female case, 86% of usable clusters are spotted