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Polygraph & Voice Stress Analysis 

Polygraph Instrument

Man has searched for the perfect Lie Detector for centuries. The polygraph is the most commonly used in today's word. The world polygraph means "many graphs." This indicates that it generates several graphs at one time. The graphs are displayed on chart paper and analyzed by a polygraph examiner to form an opinion as to truthfulness or deception.

The most commonly asked questions are:

How accurate is a polygraph examination?
The examination will be 95 to 98% accurate. The polygraph is an investigative tool to aid investigators, attorneys or a client in resolving ongong investigations or private issue.

Can the results be used in a court of law?
In criminal cases the results can only be used if all parties involved sign a stipulation agreement prior to the examination. In civil cases the results most likely will not be evidence. However, some civil court judges may allow the results depending on the case and the judges understanding of polygraph.

How long does a polygraph examination take?
As a general rule about two hours. The examiner will take as much time as needed to have good charts to form an opinion. Criminal cases can take much longer than the two hours.

Can someone beat the polygraph?
We would never say never, however it is very unlikely as the examiners have training to assure that their findings are accurate. From time to time an examination will be inconclusive. This means that the examiner can not form an opinion. There are a few people that can not be tested accurately by the polygraph. This in no way means that they are not being truthful. It very simply means that they can not be accurately tested by the instrument.

Can I give my husband, wife, boyfriend or girlfriend a polygraph test? 
The answer is yes. As long as they agree to the testing. A polygraph examiner will not test anyone that indicates that they are being forced to take the test.  

Voice Stress Evaluation.

The voice stress technology operates on the principal that the human voice has two frequencies. When a person is under high stress or lying the frequencies change and that causes micro tremors in the voice. The voice stress instrument detects the changes or lack of changes and displays them on a chart to be analyzed by the examiner. There are several types of voice analyzers on the market. Some of the analyzers use computers to display the frequencies and aid in the analysis.

The plus with voice stress analysis is that the persons being tested does not need to be present. With this type of analysis the accuracy will be less. Analysis of a persons voice without their knowledge brings up many legal issues and is not recommended.

Which is more accurte the polygraph or voice stress evaluator? The answer is who are you asking. Polygraph examiners will say they are more accurate. Voice stress will say that they are more accurate. The polygraph measures five areas for evaluation and the voice stress measures one. With this, a person would think that the polygraph would be more accurate than the voice stress evaluation. This is a very complex issue and the space provided here can not afford the room to bring out and discuss all the issues on this topic.

Employee Polygraph Testing

In 1989 the Federal Government passed the Polygraph Protection Act. Pre-employment polygraph testing is now limited to federal and local government agencies, armored car services, those dispensing controlled substances and security companies involved in national security.

Employee Theft and Misconduct

Employers may conduct polygraph test for theft, fraud or misappropriation if they can meet the following guidelines:

Prove that there is in fact a shortage or misconduct.

Prove that there is an ongoing investigation in regards to the incident.

Prove that the person to be tested had more than "just access" to the items missing or the incident under investigation. This can be from information received from an anonymous source. This can also be another employee witness an unusual transaction may by the employee in question.

Advise the employee of their rights under the polygraph protection act.

The employee must be given a form showing the purpose of the test and why they are being ask to take a test. If they refuse the employer can not take any adverse action against the employee.

There is a 48 hour waiting period after the employee receives the form. After the 48 hour waiting period the test can be given, if the employee agrees to do so. This does not include weekends and holidays.

They must be given a form showing the date, time and location of the test.

These are non-waivable rights. This means that an employee can not waive their rights under this act.

The results of the test can not be used to take any adverse action against the employee.

If deception is indicated, then the employee must be given a copy of the polygraph examiners report.

The polygraph examination must be at least ninety minutes in duration. The examiner must produce at least two polygraph charts during the examination.