voice stress accuracy

How accurate is a voice stress test

How accurate is a voice stress test? It is between 96% to 99% accurate depending on the experience of the voice analyst, the testing protocols used and the type of VSA technology used. In some ways, the voice stress analysis test is considered to be more accurate than the polygraph. The testing can be administered in person, over the phone or from any voice recording.

As big data and analytics are increasingly considered the go-to technologies for teasing veracity from volumes of information, the real truth is that people lie, sometimes quite effectively, essentially negating reams of data on credit worthiness, employment performance and personal references.

Agencies have seen their share of headlines about rogue employees passing security clearances. An insider security threat or leak can damage business and national security, ruin reputations and even cost human lives, so organizations are keen to identify deception.

Although various technologies have been applied to determining whether a person is telling the truth or not, many experts believe that no foolproof method of lie detection exists. Nevertheless, since the early 1900s people have used available technology, from measuring changes in blood pressure and pupil dilation to linguistic analysis or magnetic resonance imaging to try to sift fact from fiction.

The polygraph was invented in 1921 and is currently used by many organizations, including law enforcement, and intelligence agencies, to interrogate suspects and screen new employees. A polygraph machine looks at heartbeat, perspiration, breathing and other physical factors that are influenced by stress. Too many stress indicators could mean that a subject is feeling guilty or is worried about his response. If stress levels remain the same throughout the questioning, then no deception is detected. However, due to several flaws of the polygraph, it is slowly being phased out.

While the polygraph has been used by law enforcement in criminal investigations, more and more police departments are now using voice stress analysis in their investigations and parole programs. In fact, the voice stress test is so accurate that a U.S. federal court recently ruled that sex offenders can be required to submit to VSA examinations as part of their post-release supervision.

The voice stress testing technology is very flexible allowing various testing environments. The VSA works whether the subject is face to face with an investigator or talking over the phone. When done in person, it uses a microphone plugged into a computer to quantify and analyze frequency changes in the subject’s responses that indicate vocal stress. Or, the same thing is accomplished via the telephone’s microphone as the examinee responds to the test questions. As the subject speaks, the computer displays each voice pattern and numbers it. At the end of the evaluation, an algorithm scores the results.



But criminal investigations represent only the tip of the iceberg for an automated system that can flag human deception. Voice stress analysis technology is an invaluable tool for personnel screening, defense and homeland security, border control and airport security as well as for financial institutions, contact centers and insurance providers or anywhere where human deception is a liability. This is how accurate a voice stress test is!

The Department of Homeland Security’s National Center for Border Security and Immigration at the University of Arizona developed a screening system called the Automated Virtual Agent for Truth Assessments in Real-Time (AVATAR), which is designed to flag suspicious or anomalous behavior that warrants further investigation by a trained human agent in the field. For more information concerning this subject make sure you take a look at how accurate is voice stress analysis.

The kiosk-based automated system conducts brief interviews in a number of screening contexts, such as trusted traveler application programs, personnel reinvestigations, visa application reviews, or similar scenarios where truth assessment is a key concern. AVATAR uses non-invasive sensors to track pupil dilation, eye and body movements and changes in vocal pitch in an effort identify suspicious or irregular behavior that deserves further investigation. AVATAR has been tested in several simulation exercises and at the U.S.-Mexico border. Its first field test was in December 2013 in Romania.

In the end, the accuracy of the voice stress test or any other lie detection method is only as good as the investigator using it and the questions posed.