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Voice Stress Analyzers


DEKTOR Psychological Stress Evaluator
Model # 101

Psychological Stress Evaluator

Manufactured in the early to middle 1970's, the Dektor Psychological Stress Evaluator Model #101 was the top of the line in stress evaluators.
It’s primary attraction was it’s manufacturer’s contention that the instrument could be used with little or no training, thus avoiding lengthy polygraph schools and tuition costs.  It fell out of favor in the 1980's when studies indicated that it’s accuracy was about the same as a “flip of the coin.”

Donated by Pat Flink, Private Investigator
$100, plus shipping and handling.

Voice Stress Analyzer
Mark IX-P

Voice Stress Analyzer

Trying once again to capitalize on a market they desperately wanted to invade, Communication Control Systems, Inc. came out with it’s top of the line “Voice Stress Analyzer.” Using a lot of puffery, they touted the instrument to be as accurate as a polygraph instrument with a third of it’s cost and training time.
As large as a small suitcase, one of it’s chief advantages was it’s secrecy.  It could be used to tape record a telephone conversation for analysis later.  After all, what could be easier that interrogating suspects over the phone and using this instrument to zero in on a culprit.

Donated by Steven E. Hardwick, Polygraph Examiner.
$100, plus shipping and handling.


The "Lie Detecto" Machine
Manning Manufacturing


Manufactured by Manning Manufacturing Company in 1961, this is a simply galvanometer that was made into a toy. It has three possible results: (1) “Are you Kidding;” (2)“Little Whopper;” and (3) "Big Whopper.” It has two adjustment knobs, one for sensitivity and one for “adjustment.” Although just a toy, it is probably as accurate at the two voice stress machines shown above.




The "Truth Quest" Lie Detector
Sharper Image


Using some of the same circuitry as the two voice stress machines shown above, this miniature “lie detector" is marketed by Sharper Image. It has a series of colored light on the left side starting with green, progressing to yellow, and ending in red. This device is left on a desk in front of the person being questioned and depending on the number of the colored lights a subject’s response elicits, it is supposed to determine trughfullness or deception. It simply doesn’t work.




The"Shocking Liar" Truth Detector
Paladone Industries.


This portable lie detector is about as big as an inverted soup bowl. It is manufactutrer by Paladone in China. A test subject puts his hand into the harness on the top of the device. Once turned on, a series of lights revolve around the device for several seconds after the subject answers a question. A series of colored lights progressing from green to read light up on the front of the device to tell the “examiner” if the subject is lying. One interesting thing about this device, if it detects what it believes to be a “lie,” it sends a rather uncomfortable shock through the hand. There are two levels of pain selectable, “Low” and “High.”


"Lie Detector"


One look at the read out on this "portable lie detector" should tell you that it can't be taken seriously. It manufacturers tout it as a handheld voice-tension detector which measures degrees of vocal vibration to determine if someone is telling the truth.

Ask your subject three easy "yes" or "no" questions. De-FIB-ulator records the answers, establishing a baseline reading. Then, ask serious yes/no questions.  If the subject isn't responding honestly, the onscreen face of "Demonochio" grows a long nose and horns.

Purported accuracy is 65 percent. And it even works with cell phones!

Analog or computerized Voice Stress Analyzers are, at best, about as accurate as the flip of a coin.
Sometimes, Worse!