Welcor, the home of Truth Verification in Africa

By: Welcor  11-11-2011
Keywords: Polygraph, Polygraph Testing

Testing methods.
We offer both Voice Stress or/and Polygraph testing for fast accurate and reliable results.

Voice Stress.
Our experience is that most of the Industry is moving away from the old Polygraph testing method to the Voice Stress method as it is more hygienic, less intimidating and more subject friendly.

We would not like to get involved in the senseless arguments between the VSA and Polygraph industries. We use both methods and both methods carry merit.

Areas of operation:

GautengFreestateNorthwestNorthen Cape


Western Cape


North Africa

We need properly qualified and able examiners in:

  • Eastern Cape
  • Kwazula Natal

See some of the factual difference between the two methods.

PolygraphVoice Stress
Intrusive physiological attachments(Painful at times)No Attachments
Old science (80 years)Modern science with space age technology.
Easy CountermeasuresONLY Countermeasure is Silence
Hostile TechniquesNon Hostile Techniques
30-60% “Inconclusive” ResultsNo “Inconclusive” Results
Drugs, Age & Health skew results

Not affected by Alcohol, Drugs, Age or Health

“YES” & “NO” Answers requiredNarrative answers acceptable
Test limited to 8-14 questionsUnlimited questions in test
Must sit motionlessUnrestricted movement
Totally Analogue or with Computer to display ChartsTotally Digital (32bit). Proprietary algorithms.

Since about 81% of all people we have tested are innocent, it makes more sense to do a friendly test and keep the tested people in a positive frame of mind afterwards.

What is the principal behind Voice Stress testing?

We get this question quite a lot as most people are familiar with Polygraph test due to its exposure on the television and very few programs feature VSA test as it is a relative new technology and not as visual at Polygraph.
For this purposes the producers of programs and movies make use of old analog polygraph machines (needles & ink systems) for their display purposes.

Basically the VSA test comprises the measurement of the flexibility of the vocal cords.  As one starts to stress and enter into the “fight, flight or freeze (FOF)” mode, the body undergoes several changes to cope with the danger at hand. One of these changes is the body reduces blood to the extremities and utilizes it in the major muscle groups located mainly in the upper body.  This causes the muscles in the throat to tighten and the basic frequency of the voice changes.In the late 40’s Dr. Olof Lippold from the University College in London discovered all humans had a base frequency of between 8 to 12 hertz when in a normal state.  

As he put it in his report named PHYSIOLOGICAL TREMOR, “A slight oscillation at approximately 10 cycles per second accompanies the normal contraction of voluntary muscles. It appears to be caused by a “hunting” mechanism in the reflex that controls the muscle”

Once we enter into the FOF syndrome, this basic frequency is diminished and is significantly less.
You can read more about VSA or DVSA (Digital Voice Stress Analysis) at Dr. Gary Baker’s website.

A more intimidating test method that has its time and place. Lots of people refer to Truth Verification tests as Polygraph.

We get asked every day which of the tests is more accurate?
The answer is both at the same time, this method is called "Polystress".
The accuracy of these methods is determined by the integrity, quality of the training and experience of the examiner.

Keywords: Polygraph, Polygraph Testing

Contact Welcor

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