“Police Use of Voice Stress Analysis Generates Controversy”

Margie Wylie reports for the Newhouse News Service in a well-researched article on CVSA. Excerpt:

Police departments across the country are buying the controversial Computer Voice Stress Analyzer, which its manufacturer claims can tell when a person is lying merely by the sound of his voice. When a suspect speaks, a computer program “listens” for minute vocal shifts that, in theory, indicate stress.

The technology’s critics, citing government and university research, say the CVSA is little more than an electronic Ouija board with accuracy rates to match. At best, they say, voice stress analysis scares suspects into confessions; at worst, it can incriminate the innocent.

CVSA results aren’t admissible in most courts, under the same Supreme Court decisions that generally bar polygraph evidence.

Even so, police officers love it. Cheaper and faster than the polygraph, the CVSA can be operated with a few days’ training and without the need to “wire up” a suspect. It can also be used in the field, covertly, and on tape recordings, according to the National Institute for Truth Verification of West Palm Beach, Fla., its manufacturer.

Between 1999 and 2000, NITV added 100 new customers. So far in 2001, NITV officials say nearly 300 police departments have bought at least one CVSA. Some have bought several, and nearly all “have put their polygraph on the shelf,” said David Hughes, a retired police captain and executive director of the company.

Originating from a Cold War military project, voice stress analysis was first commercialized in the early 1970s.

NITV, founded in 1986, has a virtual lock on the law-enforcement market,according to both the company and its critics. It has sold its $10,000 CVSA to more than 1,100 police departments and trained more than 4,200 CVSA operators at about $1,300 each, Hughes said.

The company’s Web site is replete with testimonials and success stories. One Alabama police department is said to have solved a murder case 14 years cold by re-interviewing the main suspect with the CVSA. The suspect had previously taken four polygraphs given by three different examiners, all inconclusive. Confronted with three failed voice stress tests, he broke down and confessed.

Researchers counter that nothing in 30 years of studies proves that voice stress analysis works, either generally or in the specific case of the CVSA.

“Voice stress analysis is a fraud. It has zero validity,” said David T. Lykken, a psychology professor emeritus at the University of Minnesota in Minneapolis and author of the book “A Tremor in the Blood: Uses and Abuses of the Lie Detector.”

For discussion of CVSA, see the CVSA forum on the AntiPolygraph.org message board.

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