The city bought two $9,000 voice stress lie detectors banned by the U.S. military due to poor performance.

The Honolulu Police Department is using the Computer Voice Stress Analyzers from The National Institute for Truth Verification, a West Palm Beach, Fla., company founded by Charles Humble.

After using the device in Iraq, Afghanistan and Guantanamo Bay the U.S. military banned it in February 2006, claiming the results are no better than 50-50.

A study by the Pentagon's Defense Academy for Credibility Assessment determined results from the device were no better than "chance."

The device — essentially a laptop, a microphone and voice mapping software — is supposed to measure FM radio waves produced by muscles around the throat and voice box. Untruthful answers cause stressful tremors in the voice that are recorded and mapped by the software, the company says.

Humble did not return two messages left at the company's West Palm Beach office seeking comment on the defense academy study.

The company has said on its Web site that more than 1,500 American law enforcement agencies have purchased the devices in recent years.

The Honolulu Police Department bought the devices, trained two officers and began using them about two weeks ago to screen potential officers and civilian employees.

The department is using the two devices as part of a year-long recruitment pilot project. Officials said the devices were seen as a way to speed up hiring and cut costs. The program will be re-evaluated at the end of the year.

Questions surrounding the validity of the device have prompted the department to limit its use to job screening.

"A lot of other departments use them as investigative tools but we're using them for job applicants and we have other means to complete the evaluation process," said Honolulu police Chief Boisse P. Correa. "We don't use them for any criminal or internal investigations, for questioning suspects, witnesses or police officers. The (devices) are only one of many tools used to screen applicants. It's a cost-effective recruiting tool."

Honolulu police said the department consulted with city attorneys and was told the devices are permissible by law.

The Police Department also uses background checks, psychological exams, drug screening, physical examinations and written tests as part of the employment process. After the initial screening, potential officers still must complete a course at the department's training academy and a probationary field training program.

The department also said that the device has as many detractors as the traditional polygraph test. The results of either test are not admissible in state court, police said.

Tenari Maafala, president of the State of Hawaii Organization of Police Officers, said the department had not made a formal presentation to the union but he was aware of the device's use in the pilot recruitment program.

"If it will help screen applicants in order to get the best of the best, we'll certainly take a look at it," said Maafala. "You don't want to put the carriage before the horse. It would be a shame to bring guys in only to find out later they have a crazy background."

Humble, the company president, told The Arizona Republic in 2005 that the device couldn't be evaluated under laboratory conditions because stressful deviations occur only when an interrogation subject is afraid of prison or the death penalty.

But in 2004, the National Academy of Sciences reviewed voice-stress studies and concluded there is "little or no scientific basis" to consider the device an alternative to polygraph machines.

A 2005 report done for the International Association of Chiefs of Police found that "whatever the CVSA may record, it is not stress. The poor validity for the current voice stress-technology should provide a caveat to agencies considering adding voice stress to their investigative toolboxes."

Reach Peter Boylan at pboylan@honoluluadvertiser.com.