Several weeks ago, I was researching police hiring practices in Florida and I got into a conversation about voice-stress analysis. I had heard of voice-stress analysis 25 years ago, and most people probably remember the voice-stress analyses which were done on Lee Harvey Oswald's famous: "I am a patsy" statement. I had no idea, however, that voice-stress analysis was being widely used in law enforcement as a hiring and investigative tool.

David Hughes, executive director of the National Institute for Truth Verification says that more than 600 police agencies in the United States use the more expensive voice- stress analyzers costing from $5,000 to $8,000 instead of the polygraph. While the polygraph measures changes in a person's body associated with stress - alterations in heart rate, breathing, and emotional sweating, the Computerized Voice Stress Analyzer (CVSA) measures changes in voice frequency, which identifies stress that may indicate a lie.

One thing you learn pretty quickly when you talk to people about CVSAs is that opinions are polarized. There are ardent supporters and defenders of CVSAs and more than a few detractors. The Tallahassee Police Department, the Leon County Sheriff's Department and the Quincy Police Department, for example, use CVSAs, but FDLE does not.

According to those who market CVSAs to police agencies, "the CVSA has proven itself as a reliable cost effective means of determining a subject's truthfulness." Sgt. Howard Kinch, of the Quincy Police Department, for example, says that approximately 75 police agencies in Florida use CVSAs, and that the device has an accuracy rate of 98.6%.

But, personnel at FDLE cite a Department of Defense Polygraph Institute report which "...found no credible evidence in evidence furnished by manufacturers, the scientific literature or our own research that voice stress analysis is an effective investigative tool for determining deception." The report states that the polygraph is "far more accurate," has evolved over one hundred years of practice and research, and "has established validity supported by published research."

CVSAs are less expensive, more portable, and require less training to use. For example, while you can purchase a low-end CVSA for 83.95 (high-end models can cost $8.000 to $10,000), a computerized polygraph costs something like $13,000. However, even with these advantages, no Department of Defense agency uses any form of VSA for investigative purposes. And FDLE, after looking into what was written about CVSAs declined to purchase and use them.

Doubts about the validity of even the polygraph have generally kept lie detector results out of Courts, and five years ago, the polygraph test was banned for preemployment purposes. An exception, however, was made for government agencies and armored car companies. This made law enforcement and the military the main market for CVSAs. None of the local agencies I talked with, however, used CVSAs for the screening of applicants.

CVSAs are not supposed to be sold to private individuals, but a small Israeli high-technology company is marketing a CD-rom which it maintains can detect whether a subject is under stress and therefore lying. The company created the software "Truster" for the Israeli military to be used in stopping terrorists at Israeli checkpoints. But, the consumer version has already become a hit item. At only $149, the company has already sold 2,200 copies and has agreements to distribute in Germany, Singapore and South Africa. There is also a version set to be distributed in the U.S.

But, some privacy advocates, such as Privacy Commissioner Moira Scollay in Australia, express horror at the implications of these personally used lie-detector programs. "...privacy rights include the right to know that information about me is likely to be accurate." She maintains from a country where the Truster is to be marketed in March.