When answering particular questions changes in the body occurs. These physiological changes are recorded and interpreted by the Polygraph. These changes are the result of messages received through the Autonomic nervous system. “Autonomic” means automatic or involuntary, so it deals with those aspects of the body that cannot be controlled voluntarily. The individual examined is unable to control those reactions in the body.
The Polygraph instrument records these Physiological responses through four sensors. If you tell the truth you will function at you normal Physiological level. If you are asked a question to which you are going to lie, your brain will register a “threat” because you do not want to be caught in a lie. As soon as your brain registers the threat your body automatically shifts into fight or flight response.
During the Polygraph examination the threat is associated with being caught in a lie because of the possible consequences. Because the individual does not have control over physiological responses the recording of these changes in the body by the Polygraph remains one of the most effective methods of establishing truthfulness.
Voice Stress Analysis Methodology
VSA collects data from the voice. One of the physiological responses to lying is an involuntary tightening of mussels surrounding the larynx. The result is lowering of the frequency at which the subject’s voice normally oscillates. This oscillation has been termed the “Lippold Tremor”. The frequency lowering of the “Lippold Tremor” creates an unmistakable tracking. There is no way that the subject can manipulate the “Lippold Tremor”. “Playing” with the voice will make no difference. The subject is totally unable to manipulate the “Lippold Tremor”.
Unlike the Polygraph however the VSA does not require attachments. Since the Voice Micro-tremor is governed by the central nervous system and is graphically displayed in “real time” by VSA and instantly reacts to the psychological stimuli (the question) and instantly recovers to those stimuli, tests are not limited to questions as in traditional polygraph instrumentation.
The Polygraph and Voice Stress Analysis examination involves three Phases:
- Pre-Test Phase
- Data Collection Phase
- Data Analysis Phase
Paperwork will be completed and the examinee will be familiarized with the testing procedure and instruments. All Questions will be gone over with the examinee prior to being examined.
Data Collection Phase:
The examiner will administer the test and collect at least two charts recordings.
Data Analysis Phase:
The examiner will carefully review and scored each chart in order to render an opinion as to the truthfulness or honesty of the examinee’s answers.