Forensic Voice Stress Analyzer (FVSA)

The FVSA© measures all spoken frequencies, Audible and Inaudible.

The human voice is produced by a combination of the Lungs, Vocal Folds and Articulators. When a person is being deceptive over a question that has a consequence, the vocal folds constrict subconsciously and alter the frequency of uttered sound.


This automatic physiological reaction of the Vagus Nerve areas culminating in a vocal frequency change but affecting more than a dozen parts of the body cannot be consciously controlled and is not necessarily audible.

This causes the pattern captured on screen by the FVSA © to dramatically change from Diagonal to Horizontal, thereby simplifying the analysis of the test.


SKU: FVSA Category:


The use of the instrument is limited to your imagination, but some suggested uses are:




The FVSA has NO competitors, because it is a 4th Generation Totally NEW development from Australia, produced in 2006, not mimicking old Technology that has been very controversial to say the least.

The FVSA © does NOT use the Fourier (FFT) nor the Bell – McQuiston Algorithm basis of the 1940s & 1970s that other Instruments are based on & were digitised in the early 1990s.

In 2008 a Scientific paper on ‘Analysis in Speech’ mentioned that these do NOT capture the Total variation of each utterance, & also the old VSAs are claim to be measuring a small section of 8 – 12/14 Hz frequency which is a ‘muscle microtremor’. As the Microphones used by these commence registering from 20Hz – 50Hz (depending on Brand) one would wonder about these “claims”.

Most of these old Technology Instruments were originally Analogue & are still suffering from underdevelopment.

The FVSA is a Total New 21st Century Scientific Development.

The so called ‘Lie Detector’ Polygraph has been around since the 1930s with the first Training School happening in the 1940s & then finally being digitised in the early 1990s.