Voice Stress Analysis

VOICE STRESS ANALYSIS

Introduction

The first voice stress analyser was developed in 1970. The primary purpose of that instrument, the Psychological Stress Evaluator (PSE), was to provide a means of covert lie-detection. The developers reportedly conducted five validation studies. A Chief Polygraph Examiner utilized a polygraph and voice stress analyser simultaneously in the third study on actual criminal suspects. 26 cases containing 162 relevant elements have been corroborated by confession or investigation. This was reported as “real-world”, high stress test situations in which VSA evaluation provided correct results in all elements for a success rate of 100%.

Voice Stress Analyser

McQuiston, Ford and Bell are known as the “fathers of voice stress”. The Forensic Voice Stress Analysis (FVAS)tm was developed by Dr E Gary Baker, Ph.D. The FVAS function is based upon neurological changes caused by stress. There exists in all animals a phenomenon known as muscle micro-tremor. These tremors are minute oscillations that exist in the working muscles of the body when muscles are in use. They diminish in magnitude in accordance with the increase in the level of stress. Because the source of the stress data is neurological, reaction is instantaneous.