The FVSA © measures All spoken frequencies audible & inaudible. Combining our new noise suppression microphone and our software, our frequency measurement is from 8 Hz - 16 Khz.

The Human voice is produced by a combination of the Lungs, Vocal Folds & Articulators when a person is being Deceptive over a question that has a consequence, the Vocal Folds constrict subconsciously & alter the frequency of uttered sound. This physiological reaction cannot be controlled nor is it necessarily audible.

This causes the Voice Pattern captured by the FVSA © to change from Diagonal to Horizontal allowing the Analyst to note the change on the screen instantly.

The Instruments that base the measurements on the so-called muscle "micro tremor" are restricted to only a very minor component of the voice & there is even some training based on 1980s era theory of some misguided individuals that the FM dissipates from the voice ( More FM = less stress , Less FM = more stress). 

This is impossible and has been proved many, many times over.

The average audible frequency ranges of the Human Voice are  =  Adult Male :- 85 - 155Hz, Juvenile & Females :- 165 - 255 Hz

Human vocal audible range is 80 - 1100 Hz, so an Instrument only measuring 8 - 12 Hz must be  vastly inferior to the 21st Century Instrument, the FVSA ©.