Careful What You Say...Because Your Voice Doesn't Lie

October 20, 2006 - Posted at 6:31 p.m. CDT

GREENE COUNTY, AR -- Law enforcement agencies have been using the polygraph test for years as an investigative tool.  The invasive test measures respiratory activity by placing rubber tubes across the examinee's chest. "Sweat gland" activity is recorded by placing two small attachments to the fingers or palm of the hand and cardiovascular activity is recorded by a blood pressure cuff.  But the test does not recognize voice analysis.

A different test can tell if you're lying...just from the way you answer a question.

John Slater worked in law enforcement for 18 years before he retired.  The former commander of the Criminal Investigation Division of the White County Sheriff's Department now works as an instructor for the National Institute for Truth Verification....teaching others how to find the truth.

"It's an investigative tool, it's not going to make the final determination of anything but as I said earlier, it has the flashlight gives you the sense of direction to go," said Slater.

His weapon...the Computer Voice Stress Analyzer.  It's used by more than 1500 agencies nationwide, including the military, NASA and insurance companies.

"With the polygraph, you have three answers that you will get either a deceptive response, or a non deceptive response or an inconclusive.  With the CVSA, there's deception or no deception, there are no inconclusive at all.  When we test, we'll know at that point whether there is deception or no deception, whether the person is being honest with us or not," said Slater.

In order for the test to work there has to be an element of jeopardy or a reason for the person taking the test to be a little bit nervous or anxious.  Arkansas is a one-party state...meaning legally, a person can record a conversation without the person's knowledge.

"A little girl had called in an alleged abduction, an attempted abduction and the detective that talked with the girl recorded the interview and actually did a test off of the recording and she showed deception in her statements," said Slater, "He went back and confronted the girl and she admitted that she lied about it and had made the whole thing up to get attention."

Like a polygraph, the results are not admissible in court...but they can be used for defense purposes.

"When we are analyzing charts or conducting a test, being nervous or having high blood pressure is not going to have any bearing on this at all.  The only way to defeat this instrument is just by not taking it," said Slater.

A basic CVSA unit costs just under $10,000.  Federal grants are available to law enforcement for funding.