NYC Private Investigators and people all around the world are becoming entranced with what goes on behind the scenes in computer forensics. Some of the technology that you may come across on some TV shows can seem far-fetched or unbelievable, but how far off is Hollywood from the reality of what the New York Private Detective can have at their disposal. Voice Stress Analysis, more commonly known as VSA, is one of those unbelievable technologies that are within our grasp.rnThe purpose of this article is to educate you about this forensic tool that can be used to determine whether someone is telling the truth or being deceptive. We live in a time, where new technologies and new applications for old ones, are being developed at a faster pace. Just like law enforcement today, people from the earliest times have sought some foolproof method for detecting deception. Astute observers noted that guilty persons, during interrogation, often use certain body language or exhibited signs that could be associated with guilt: a darting eye, dry mouth, a hand over their mouth when answering, sweating, yawning, or uncontrolled body movements. Over time, there came breakthroughs in the medical understanding of the observed behavior.rnThe sciences of psychology and physiology lead to the invention of equipment designed to measure changes caused by how the body reacts to stressful situations helping
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• In 1895 Cesare Lombroso invented a device called a plethysmograph which was used in lie detection. It measured changes in blood pressure.
• In 1897 Harold Sticker suggested measuring galvanic skin response (changes in electrical conductivity of the skin, caused by sweating) as a method of detecting deception.
• In 1914 Vittorio Benussi studied the breathing rates of individuals and how those rates differed depending on whether the person was lying or telling the truth.rnAs we now know, these psycho-physiological (mind and body) stress reactions cannot only be measured, they can be recorded. The polygraph, the first instrument designed to measure and record those reactions, was developed by John Larson in 1926 and improved by Leonardo Keeler soon after. It is now a well-established investigative tool that has been the backbone of lie detection. We have already found a way to use the physiological responses of blood pressure, breathing, and the skin to aid in lie detection. So what came next in biometrics, and is increasingly being used, are the autonomic responses in the vocal chords, the human voice. In the 1960’s voice stress analysis (VSA) began to be used experimentally by the military. However, like many technologies, it didn’t start gaining ground until the computer boom in the1980’s, and received harsh bias scrutiny from the competition.rnThe VSA introduced in the sixty’s was an alternative to the polygraph, and completed in January 1971 by Messer’s Wilson Ford, Alan Bell, and Charles McQuiston all who were former Army Officers. Their device, called a Psychological Stress Evaluator (PSE), measured stress in the voice and was not a “lie detector” per se.rnThe foundation of VSA technology is that a person’s voice emits detectable fluctuation in both AM (amplitude modulation) and FM (frequency modulation) frequencies called micro tremors. When you listen to a person speaking, you hear the AM which rides atop the FM, which is undetectable to the human ear. Under the stress created from a deceptive response there is a reduction in the FM frequencies, causing the micro tremors to increase. It is an involuntary autonomic response detectable with a microphone and a computer running the proper software. The skilled examiner then analyzes the person’s voice patterns looking for these frequency discrepancies. VSA works for any language whether the subject is face to face or on the phone. Drugs, alcohol and medical conditions do not affect the tests. Voice recordings that are years old can be used by
New York Private Detective to solve cold cases. And, there are no known countermeasures. A person cannot manipulate his voice frequencies the way he may be able to manipulate blood pressure, breathing, and skin response. Subjects experience less stress caused by the interrogation as only simple yes and no questions are needed. And, when face to face, the subject only has a microphone attached. When compared with a polygraph, the VSA technology is easier to use, faster to administer, less stressful, cheaper, and 98% accurate. Like the polygraph, VSA is a tool for getting at the truth. rnVSA technology is currently recognized in 43 states. Government offices and insurance companies are also using VSA software. Most people don’t realize that for years, insurance companies have recorded their customers’ conversations when they call to make claims. Suspicious claims are evaluated utilizing VSA technology. In a Department of Defense survey of law enforcement agencies that used the software they found that approximately 85% of the respondents called the technology extremely accurate or very accurate.rnBecause the only hardware required is a microphone attached to a computer or digital recorder, it can be used in the field. The U.S. Special Forces used VSA on the battlefield in Iraq and have gone house to house with it. Unlike polygraph tests, voice stress analysis does not require a sterile environment. VSA examinations provide definitive results, there are no inconclusive results. Either the subject was being deceptive or they were being truthful. For this reason you will often read that VSA is a tool used for validating the truth more than for detecting lies.rnIn addition to its affordability and ease of use, perhaps one of the biggest advantages that VSA offers is that it can be done covertly. A recording can be made and examined later. This can be done over the phone or through a hidden microphone. Voice stress analysis has proven that it is the next step in truth verification technology.rnFor more information on NYC Private Investigators and the methods used by the New York Private Detective in solving cases with Voice Stress Analysis (VSA) Technology go to
www.newyorkcity-privateinvestigators.com/.