NCJ Number
196940
Journal
Polygraph Volume: 31 Issue: 2 Dated: 2002 Pages: 129-134
Editor(s)
Deedra Senter
Date Published
2002
Length
6 pages
Annotation
This article reports the results of a study that measured, analyzed, and recorded voice pitch, intensity, and duration for the analysis of voice from tape recordings for use in lie detection.
Abstract
This article presents results from a study that looked at detection deception through an analysis of voices in respect to showing the pitch, intensity, and duration. Materials taken from criminal cases, covering 3 male subjects were analyzed. The crimes involved were larceny and rape. Analysis was made of 75 answers to relevant crime questions from polygraph tests in these real criminal cases. The answers were verified as deceptive by subsequent confession or medical jurisprudence. The duration was calculated for each answer based on records of the pitch indicator. A pitch was analyzed by using the records obtained by the pitch indicator. The intensity was analyzed as in the case of pitch analysis which was difficult. Finally, a sonogram was used in voice identification. The difference in the pitch, intensity, and duration of the voice between deception and truth has been and remains unclear. It is not known whether pitch increases or decreases when a deceptive answer is given. The results of the analysis of intensity showed no sign of increasing or decreasing of voices in intensity during the questioning. However, analysis on the duration of subjects’ answers showed a higher detection rate than pitch or intensity but it was not applicable in actual cases. From these results, using pitch, intensity, and duration of voices as a means to detect deception appears slim. Tables, references