Voice Stress - VSA Vs LVA

VSA Vs LVA

VSA is distinct from Layered Voice Analysis (LVA). Commercial VSA utilizes the inaudible microtremors (range: 6–12 Hz) in the voice to detect high stress in the speaker's words. High stress in situations where there are potentially dire consequences for the speaker is typically defined as Deceptive Stress. The microtremor is a reliable parameter as it is involuntary and cannot be affected by the speaker at will. VSA microtremor DOD was used to a high degree of reliability during the US Vietnam war effort, as an alternative to the time-devouring process of polygraphy. The US Counterintelligence Electronic Division first identified the use of microtremors when using spectrography in covert telephone monitoring operations.