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Polygraph vs. CVSA

The Internet is replete with web sites offering voice stress examinations. Some offer such testing "over the phone." They maintain that voice stress, CVSA, testing is more accurate that polygraph testing. THIS IS SIMPLY NOT TRUE. To be more specific, voice stress testing (CVSA) is not polygraph testing.

The accuracy of the CVSA has been studied ad nauseam since it's inception in the mid 1980's. Each study has shown that the CVSA is about as accurate as the flip of a coin. It has been rejected as "junk science" by every agency that has looked into using it. Some of the studies are printed below for your review. The Computer Voice Stress Analyzer, designed by a former Indianapolis Police Department officer, claims to assess truthfulness by measuring changes in one's voice. The designer, Charles Humble, is now the chairman and CEO of the National Institute for Truth Verification, which makes the machines. But several scientific experiments have shown the machine, which went on the market in 1988, is no more than 50 percent reliable -- in other words, a coin toss.

But, you don't have to take my word for it. The manufacturer conceded in a product liability lawsuit in California that the machine can't measure whether someone is lying. In San Diego, murder charges were dropped against two teenagers after it was determined their confessions were coerced after they flunked voice stress tests. One of the boys sued the National Institute for Truth Verification, and Charles Humble, claiming the analyzer was used to get the false confession. In a court filing, the Charles Humble: "NITV acknowledges that the CVSA is not capable of lie detection" Humble, a trained polygraph examiner, said his company doesn't claim the machine detects lies.

Accuracy: Polygraph vs. Voice Stress (CVSA)





Barland, Gordon H.

University of Utah


Brenner, Malcolm, Branscomb, Harvie, & Shwartz, Gary E. Oregon, MIT and Yale

"Inappropriate for lie detection"

Bersh, Philip J.

Temple University, Study for US Army


Commonwealth of Virginia, Report of the Dept.of Commerce

"Not an effective method for the

determination of deception"


Blum, Richard H. & Osterioh, William

Stanford University


Horvath, Frank

Michigan State University

"at chance level"

Edel, Eugene C. & Jacoby, Jacob

Study for U.S. Government


Kubis, Joseph F., Fordham

University, Study for U.S. Army

"identical with chance"

Horvath, Frank S. & Reid, John E.


Link, Frederick C.

U.S. Army

"not used in military law enforcement"

Lahri, S.K. & Ganguly, A.K.

Government of India


Lynch, Brian E. & Henry, Donald R., Royal Ottawa Hospital, Canada

"approximately chance"

Podlesny, John A. & Raskin, David C.

University of Utah


Nacheson, Israel, Bar I Ian

University, Study for Israel Police

"unreliable and invalid"


Raskin, David C. & Hare, Robert H.

University of British Columbia


National Security Agency, U.S. Dept. of Defence

See "Use of polygraphs …"

"insufficiently reliable"

Slowik, Stanley & Buckley, Joseph P.


Suzuki, A., Watanabe, S., Takono, Y. , Kosugi, T. & Kosugi, T. National Inst. Of Police Science, Tokyo, Japan


"not above chance, not reliable or useful"

Wicklander, D. & Hunter, F.


U.S. Air Force

See "Use of polygraphs …"

"not useful"

Widacki, Jan & Horvath, Frank

Jagolian University, Poland


Vandercar, D.H., Greaner, J., Hibler, N.S.,

Spielberger, C.D., & Boch, S., University of

South Florida

"analysis is subjective and poorly

understood … primitive"

Lie Detection Testing Over the Phone?

This latest wave in the CVSA farse is to offer testing over the phone. Lie detection testing over the phone? An utterly absurd idea. Yet each day, people are scammed by their promises. Don't allow yourself to be cheated by these scamsters.

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