Differences between a polygraph test and a voice stress test are many. First of all, the polygraph has a certain psychological advantage of examinee being secured to a chair with 4 wired connections made to their body. But these are unnatural attachments and there are strict requirements that do not allow that the slightest movement can be made or the test is corrupted, which can sometimes add enough stress to affect the results. Also, there are countermeasures, or ways to trick the polygraph that, if not caught, they can easily allow a test to be falsely passed.
On the other hand, the voice stress test can be administered in person or over the phone with NO attachments or anything touching the examinee allowing the examinee to not be restricted in movement. The voice stress test is so accurate
What are some other differences between a polygraph test and a voice stress test?
The polygraph uses aggressive testing techniques, whereas the voice stress testing uses more relaxes and friendly techniques.
The polygraph is an older technology, but the voice stress analysis test uses modern science and technology.
The polygraph test can have inconclusive results and false positives. However, the voice stress analysis testing does not have these issues.
The voice stress analysis was developed for United States Military Intelligence looking for an alternative to the polygraph. Even insurance companies quietly use it to screen for suspected false loss claims. The VSA is used by the California Highway Patrol, the Los Angeles County Sheriff Department, over 200 California police agencies, and nearly 2000 law enforcement agencies across the country instead of the polygraph.
The voice microtremor, which is what the voice stress analysis tests measures, is governed by the central nervous system and reacts to the psychological stimuli, the test question, in the same time frame as does polygraph. However, the difference between the polygraph test and a voice stress test is that the microtremor recovers within 2-3 seconds, while the parts of the body that the polygraph measures takes 25-35 seconds to recover in between questions. As a result, the voice stress analysis testing process is quicker and more efficient. For additional info with regards to this matter please take a look at voice polygraph test.
For some special situations where privacy can assist with embarrassment or security issues, testing can be done with equal accuracy over the phone. Accordingly, this technology is rapidly replacing the polygraph at many law enforcement agencies. There are several independent and unbiased studies conducted regarding the accuracy of voice stress analysis. Each of them show the high accuracy of the voice lie detection.
No other type of lie detector testing has received such a strong endorsement by government and law enforcement agencies. Some say the differences between the two types of lie detector tests is comparing the polygraph test to the old style wired telephone lines and voice stress lie detector tests as being like modern digital telephone service.