Services Available

Testing methods.

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

The best testing method is a combined technique called "PolyStress" ©.

With Polygraph we test the person's autonomic nervous system and with Voice Stress we test the central nervous system.

The PolyStress technique test both nervous systems simultaneously thus having a lot more reliable result.
There is a specific method to do this test to be able to relay on the result as it differ from both Polygraph and Voice stress. Only the examiners listed on the APAVSA website have been trained in the technique and can use and report on it. It is not merely doing two different tests or using both techniques at the same time. This is a very advanced test method and should not be attempted by examiners not purposely trained and qualified.

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:

Gauteng Free State North West Northern Cape
Limpopo Western Cape Mpumalanga North Africa

We need properly qualified and able examiners in:

• Eastern Cape
• KwaZulu Natal

See some of the factual difference between the two methods.


Polygraph (ANS) Voice Stress (CNS)
Intrusive physiological attachments(Painful at times) No Attachments
Old science (80 years) Modern science with space age technology.
Countermeasures Attempted ONLY Countermeasure is Silence
Hostile Techniques Non Hostile Techniques
30-60% “Inconclusive” Results (Examiner dependent) No “Inconclusive” Results
Drugs, Age & Health can skew results Not affected by Alcohol, Drugs, Age or Health
“YES” & “NO” Answers required Narrative answers acceptable
Test limited to 8-14 questions Unlimited questions in test
Must sit motionless Unrestricted movement
Totally Analogue or with Computer to display Charts Totally Digital (64 bit). Proprietary algorithms.

Since about 82% 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?

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.


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.

What is the principal behind Polygraph testing? Click HERE (Wikipedia)

Ensure you use only registered examiners who have the proper training and use regestered software (DVSA/FVAS version 4 software is illegal in South Africa)

To all qualified Examiners, if you were issued with the DVSA/ FVAS version 4 software contact us to find out how you can upgrade your software to the new Expertosvsa version 5 software.

South Africa has no official standard for VSA Analyzers and the rest of the world does not accept SA qualifications if not on International standard and registered with an International Association.

Due to this loophole there are Instructors presenting their own version of VSA courses with sub-standard or pirate software claiming false accreditations and therefore not recognized by the International community.

Welcor TVC withdrew from SAPAVSA (South African Polygraph and Voice Stress Association