Voice Stress Detection

Voice Stress Detection

What is VSD?

VSD is a technology that aims to infer deception from stress measured in the voice. An examiner typically records the human voice using a microphone, and the technology is based on the tenet that the non-verbal, low-frequency content of the voice conveys information about the physiological and psychological state of the speaker. Typically utilized in investigative settings, the technology aims to differentiate between stressed and non-stressed outputs in response to stimuli (e.g., questions posed), with high stress seen as an indication of deception.


Training in voice and/or biofeedback polygraphy is provided by appointment. We have the only multiple polygraph manufacturer accredited instructors in South Africa. 

We have two courses available:

Standard & Advanced

Standard duration1 Week

Advance duration4 Week


Add 2 Days to Include Truth Extraction and SCAN technologiesP.O.A.

Course Outline

Course designed using AVSAPRO systems
Course material covers all the essentials required to produce high quality, reliable results.
Biology, psycho-physiology, psychological set, Complete pre-test, in-test and post test procedures, Question Constructs, Software Instruction.
Embraces original polygraph methodologies.
As the software utilises a neural network processor (Artificial Intelligence) the training module is shortened considerably. This technology performs 90% of the work and delivers same accuracy levels as traditional polygraph