NCJ Number
18486
Date Published
1973
Length
54 pages
Annotation
EVALUATION OF THE CAPABILITY OF VOICE ANALYSIS AS A LIE DETECTION TECHNIQUE AND COMPARISON OF THE EFFICIENCY OF TWO SUCH DEVICES WITH THAT OF THE POLYGRAPH.
Abstract
TWO VOICE-ANALYSIS TECHNIQUES WERE EVALUATED AS LIE DETECTION DEVICES IN A SIMULATED THEFT EXPERIMENT WHICH UTILIZED 174 SUBJECTS. ONE GROUP OF SUBJECTS (N - 137) WAS EXAMINED WITH THE POLYGRAPH AT THE SAME TIME AS VOICE RECORDINGS WERE TAKEN. A SMALLER GROUP (N - 37) WAS TESTED ONLY WITH VOICE RECORDINGS. BOTH GROUPS OF SUBJECTS CONSISTED OF MALE AND FEMALE UNIVERSITY STUDENTS. THE RESULTS FAILED TO DEMONSTRATE THAT EITHER OF THE VOICE-ANALYSIS TECHNIQUES WAS EFFECTIVE IN IDENTIFYING THE THREE BASIC ROLES (THIEF, LOOKOUT, INNOCENT SUSPECT) OF THE SIMULATED THEFT. IN CONTRAST, THE POLYGRAPH ACHIEVED AN ACCURACY SCORE OF 73 PERCENT, A VALUE COMPARABLE TO THAT OBTAINED IN PREVIOUS STUDIES USING THE SIMULATED THEFT PARADIGM. INDEPENDENT RATERS, WHO KNEW NOTHING ABOUT THE CHARACTERISTICS OF THE PERSONS EXAMINED, ALSO OBTAINED SIGNIFICANTLY HIGH ACCURACY SCORES IN THE EXAMINATION OF THE POLYGRAPH CHARTS (50 60 PERCENT). ALTHOUGH THE OVERALL RESULTS OBTAINED FROM VOICE RECORDINGS WERE NOT STATISTICALLY SIGNIFICANT, LOWER VOICE-ACCURACY WAS OBTAINED WITH POLYGRAPH-TESTED SUBJECTS THAN WITH THOSE WHO WERE EXAMINED WITHOUT THE POLYGRAPH. A SUBSIDIARY RESULT CONCERNS THE RATINGS OF TAPE MONITORS WHO WERE PRESENT DURING ALL INTERROGATION SESSIONS. BASING THEIR JUDGMENTS ONLY ON THEIR IMMEDIATE GLOBAL IMPRESSIONS, THEY WERE ABLE TO DISCRIMINATE BETWEEN THE THIEF, LOOKOUT, AND INNOCENT SUSPECT WITH A SIGNIFICANT DEGREE OF ACCURACY. THIS CAPABILITY TOGETHER WITH THE HIGHLY SIGNIFICANT ACCURACY SCORES OF THE POLYGRAPH EXAMINERS, DEMONSTRATE THAT THE SIMULATED THEFT PROCEDURE IS VALID FOR LIE DETECTION, RESEARCH, IN THAT IT INDUCES IN SUBJECTS A SUFFICIENT DEGREE OF EMOTIONAL RESPONSIVENESS AND INVOLVEMENT TO ENABLE THE POLYGRAPH EXAMINERS AND TAPE MONITORS TO DIFFERENTIATE AMONG THE THREE BASIC ROLES OF THE SIMULATED THEFT SITUATION. THE FAILURE OF THE VOICE-ANALYSIS TECHNIQUES TO DETECT THESE DIFFERENCES CANNOT, THEN, BE ATTRIBUTED TO INSUFFICIENT EMOTIONALITY IN THE SUBJECTS. RATHER IT WOULD SEEM TO BE A MATTER OF INSENSITIVITY OR OTHER INADEQUACY IN THE DEVICES THEMSELVES IN THEIR PRESENT STATE OF DEVELOPMENT. (AUTHOR ABSTRACT)