We often receive enquiries about Voice Stress Analysis and many people think that it is the same as Polygraph Testing. This is however not the case and there are some fundamental differences.
Polygraph testing has been around for a lot longer than VSA – the first commercial polygraph was patented by John Larson in 1921.
Polygraph records three channels to identify physiological changes consistent with deception – Respiration, Galvanic Skin Response and changes in Blood volume/Cardiac Output.
VSA records “microtremors” produced in the voice box to detect deception.
ABC had an interview with the inventor of CVSA “Dr” Humble to view the video click here.
polygraph test vs voice stress analysis