Research and Recent Studies on the Science of Voice Stress Analysis

While the Computer Voice Stress Analyzer (CVSA®) is often considered an emerging technology, this cutting-edge truth verification system has been established as an important investigative tool by law enforcement for a long time now. From the discovery of how voices change in relation to stress in the 1970’s to today’s studies on the computerized technologies that enhance the system’s capabilities, many in the scientific community have been intrigued by the capabilities of the CVSA and the hidden messages in the human voice. With this in mind, we will endeavor to make the studies that underpin the scientific validity of the CVSA available and easy-to-understand so all CVSA practitioners will have a better understanding of the complex road the CVSA has travelled, from its humble beginnings to its domination of the truth verification market today.

Scientific Studies on the CVSA®

Shadows into Light: The Investigative Utility of Voice Analysis with Two Types of Online Child-Sex Predators

Over 390,000 child sexual abuse victims in the United States have not yet been identified. Due to the increased prevalence of Internet driven child-sex offenders (e.g., child pornographers and travelers), detection becomes more elusive, and disclosure elicitations are more challenging for law enforcement…

Scientific Study Summary: Chapman, James. “Long-term Retrospective Field Evaluation Of Voice Stress Analysis In A Criminal Justice Setting.” 2012

How Did the Chapman Study Demonstrate Voice Stress Analysis Validity for Law Enforcement? In 2012, Professor Emeritus James Chapman conducted a retrospective analysis regarding the use of voice stress analysis (VSA) in law enforcement settings. As the Former Director...

Scientific Study Summary: Hasan, Y. (2017). “Violent Video Games Increase Voice Stress: An Experimental Study.” Psychology of Popular Media Culture 6(1), 74-81.

In the field of law enforcement, voice stress analysis technology such as the Computer Voice Stress Analyzer (CVSA ®) is used in a range of applications, including criminal investigations, employment interviews, and immigration investigations. The CVSA detects changes...

Scientific Study Summary: “Analysis of Voice Stress in Call Centers Conversations.” Grazyna Demenko and Magdalena Jastrzebska. 2012

Prioritizing Emergency Calls: How Can Dispatchers Use Voice Stress Analysis? The Computer Voice Stress Analyzer (CVSA®) has shown great value as a tool for law enforcement professionals to detect deception. It is commonly used to help solve criminal cases, screen job...

Scientific Study Summary: “An Acoustic Method to Quantify Perceived Vocal Tremor,” Marios Fourakis University of Wisconsin 2010

Diagnosing Speech Disorders: Can Voice Stress Analysis be Used in the Medical Field? Although Computer Voice Stress Analysis (CVSA) is most commonly used to interview suspects and witnesses in criminal investigations, the technology’s ability to identify vocal tremors...

Scientific Study Summary: “Structured Interview Assessment of the Field Use of Voice Stress Analyzer Technology.” Department of Defense, 30 Mar. 2007.

How is Voice Stress Analysis Technology Viewed in the Law Enforcement Community? In the mid-2000’s, the Department of Defense set out to conduct a qualitative study to investigate the validity and reliability of voice stress analysis (VSA) technology in a military...

Scientific Study Summary:“Policy Review: CVSA is a Valid Law Enforcement Tool.” Hugh Wilson Ridelhuber and Patrick Flood. 2002

What are the Benefits of Voice Stress Analysis for Law Enforcement? In August 2002, Dr. Hugh Wilson Ridelhuber and Dr. Patrick Flood submitted a policy review to the Law Enforcement Executive Forum to demonstrate the validity of the Computer Voice Stress Analyzer...

Scientific Study Summary: Cistaro, Victor, Ph. D. “A Comparison Between Decision Accuracy Rates Obtained Using Polygraph and the Computer Voice Stress Analyzer in the Absence of Jeopardy.” The Department of Defense – Polygraph Institute, Aug. 1995.

How Did the Department of Defense Verify the Theory Behind Voice Stress Analysis? In 1995, a new type of truth verification technology was making its mark in the law enforcement community: the Computer Voice Stress Analyzer (CVSA®). First introduced by the National...

Scientific Study Summary: Eden, G. and Inbar, G.F. “Psychological Stress Evaluators: EMG Correlation with Voice Tremor.” Department of Electrical Engineering Technion, Israel Institute of Technology, Haifa, Israel. 1976

How Did EMG Experiments Lead to Contemporary Voice Stress Tests? Over the course of about a decade, J. Gary Eden and Gideon F. Inbar—two researchers in the Department of Electrical Engineering Technology at the Israel Institute of Technology—conducted multiple studies...

Scientific Study Summary: “The Rhythmical Activity of Groups of Motor Units in the Voluntary Contraction of Muscle.” O.C.J. Lippold, J.W. T. Redfearn, and J. Vuco. University College London 1957

What Early Scientific Studies Led to the Development of Computer Voice Stress Analysis? The scientific research behind the Computer Voice Stress Analyzer (CVSA) goes back over sixty years. One of the earliest studies, published in 1957 by O.C.J. Lippold, J.W.T....

To help you navigate through these studies, each question corresponds to an answering in-depth summary of a scientific study