NCJ Number
31260
Date Published
1975
Length
13 pages
Annotation
THIS PAPER DESCRIBES THE ANALYTICAL STUDIES LEADING UP TO THE DEVELOPMENT OF SASIS (SEMI-AUTOMATIC SPEAKER IDENTIFICATION SYSTEM) WHICH UTILIZES COMPUTERS TO ANALYZE AND COMPARE SEGMENTS OF SPEECH.
Abstract
IN THE SASIS, SEGMENTS OF SPEECH ARE EXTRACTED FROM TWO SPEECH UTTERANCES AND ARE COMPUTER-ANALYZED TO YIELD A STATISTICAL MEASURE INDICATING WHETHER THE UTTERANCES WERE SAID BY THE SAME OR DIFFERENT SPEAKERS. THE ANALYTICAL STUDIES INVOLVED THE COLLECTION AND PROCESSING OF SPEECH DATA FROM OVER 250 SPEAKERS FROM WHICH WAS EXTRACTED OVER 35,000 PHONETIC-EVENT TOKENS. A STUDY OF THE DISCRIMINATING POWER OF INDIVIDUAL PHONETIC EVENTS, ALONG WITH A STUDY OF COARTICULATION EFFECTS ON THESE SAME EVENTS, WAS CONDUCTED. A UNIQUE SET OF 30 FEATURES WAS DEFINED FOR EACH OF THE RESULTANT 13 PHONETIC CATEGORIES USED BY THE SASIS IN CARRYING OUT SPEAKER IDENTIFICATION. A WEIGHTED EUCLIDEAN DISTANCE MEASURE WAS SELECTED FOR MEASURING SPEAKER SIMILARITY WITHIN A PHONETIC CATEGORY, AND A DESENSITIZED FISHER DISCRIMINANT WAS INCORPORATED TO COMBINE THESE INDIVIDUAL DISTANCE MEASURES INTO AN OVERALL MEASURE OF SIMILARITY BETWEEN THE SPEAKER OF TWO SPOKEN UTTERANCES. A SET OF LIKELIHOOD TABLES, INDEXED BY SIMILARITY MEASURE AND THE PHONETIC EVENTS USED, WAS DERIVED TO DETERMINE THE PROBABILITY THAT THE UTTERANCES WERE UTTERED BY THE SAME OR DIFFERENT INDIVIDUALS. (AUTHOR ABSTRACT MODIFIED)