Bloomsburg, Pennsylvania Press Enterprise writer Michael Reich reports on Computerized Voice Stress Analysis (CVSA). Excerpt:
HAZLETON — When someone lies to police here, a “truth verification” machine might be able to sense the fib by recording changes in a person’s voice.
Hazleton Police Chief Edward Harry says the machine has led to confessions in 75 percent of the roughly 500 cases it has been used in here over the years. The national average is 35-40 percent, he said.
“That just shows how many times that we’ve got confessions and made arrests on cases that we wouldn’t have been able to do that,” the chief said.
But some have criticized the computer voice stress analyzer (CVSA) for inaccuracy. A 1996 Department of Defense review found it had a success rate of only 49.8 percent on 109 test subjects, some of whom took part in a mock crime that involved the theft of $100, according to the Web site www.voicestress.com.
Like polygraph lie detector tests, results from a CVSA are inadmissible as evidence in court. But more and more departments are turning to the machine, Harry said.
“Other departments are starting to see that this really works,” he said.
CVSA, like polygraphy, is a pseudoscientific fraud and only “works” to the extent that it elicits confessions from naive and gullible suspects.