The REAL TRUTH About Voice Polygraph/ Voice Stress Analysis
Very few professionals have extensive experience with BOTH popular types of lie-detection.
I do. Since I also offer the traditional 'wired' examinations (see www.PublicPolygraph.com), I know the advantages --and disadvantages-- of both 'wired' polygraph and 'voice' polygraph.
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Wired:
I like the psychological advantage of them being secured to a chair with 4 wired connections made to their body (chest, stomach, left upper arm, and fingers on right hand).
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 themselves sometimes add enough stress to affect the results.
And, because with 'wired' polygraph the client can only have 3 or 4 relevant questions (questions about the client's issue or situation) asked, the exam often leaves more questions unanswered than answered.
Also, the Internet is full of 'How To Beat A (wired) Polygraph' advertisments; known as 'countermeasures', if not caught they can easily allow a test to be falsely passed.
Voice:
I like: --more questions can be asked
--it is so powerful if used secretly in contract negotiations and other private discussions to get unfair advantage that criminal laws now require written permission to use it
--NOTHING is attached to or touching the examinee
--developed for United States Military Intelligence looking for an alternative to wired polygraph
--insurance companies quietly use it to screen for suspected false loss claims
--used by the California Highway Patrol, the Los Angeles County Sheriff Department, nearly 200 California police agencies, and nearly 2000 law-enforcement agencies instead of 'wired' polygraph examinations!
--The voice �micro-tremor� is governed by the central nervous system and reacts to the psychological stimuli (the question) in the same time frame as does polygraph, BUT the difference being that with voice, the �micro-tremor� recovers almost instantly, while with polygraph the required recovery time is 25 seconds or more inbetween questions. The process is therefore far more user-friendly as there is no artificial waiting time between question sets.
--For some special situations where privacy can assist with embarassment or security issues, testing can be done with equal accuracy over the phone.
--NO 'countermeasures' (no way to 'trick' or 'beat' this technology!)
Voice lie detection, following a paralinguistic pre-test interview, is very accurate. The figures most often cited are in the 95% - 98% range.
Used successfully by US military troops on terrorists in war zones in combat situations in Iraq and in Afganistan.
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.
Following the 9/11 attack on America, Congress provided President Bush with The Airport Security Federalization Act of 2001, which he signed into law. This includes the provision that airports will �provide for the use of Voice Stress Analysis or other technologies to prevent a person who might pose a danger to air safety from boarding the aircraft��. Congress and this provision further legitimized the use of voice stress analysis as a means of truth verification.
No other type of lie-detection has received such a strong endorsement.
Comparing the two types of lie-detection: Some have compared wired polygraph as being like old-fashioned wired telephone lines and Voice Lie Detection as being like modern digital telephone service.
Many states have enacted legislation regulating the use of voice lie detection on persons without their express consent in advance, yet even further endorsing the validity of voice lie detection.
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More importantly: I have conducted BOTH exam types at the SAME time on the SAME person many times; the final outcome (Pass or Fail) matched on each every time.
The wired polygraph industry does not like voice-based lie-detection; the voice polygraph industry does not like wired-based lie-detection. Some call it the 'Toyota and Nissan' comparison: both do their job, similar yet different.
Each side will try to 'sell' theirs as being the best and the other as less. Each will cite 'studies' and 'statistics': some are accurate, some are self-serving.
I know both and perform both; I am certified for both.
Only someone experienced with both and who offers both can give an accurate & unbiased opinion.