People frequently lie in their lives. Research shows most people lie every day. Typically, most of the lies they tell are insignificant, with no real consequence.

For instance, telling your partner, they look good in that dress when you think the opposite is a small lie that helps them maintain their confidence. Why tear someone down when you can lie and let them feel good about themselves? Does it matter what you think they look like in that dress anyway?

Then there are lies with significant consequences. Liars in the workplace can be challenging to spot during pre-employment screening. They may have sociopathic personalities concealing their true intentions. Hiring a rogue employee can damage a business or organization.

For this reason, government agencies like the NSA, FBI, and CIA implement polygraph testing for all prospective candidates. They also operate a polygraph policy for their employees. Insider leaks, as in the case of Edward Snowden, can damage these organizations’ credibility and security.

While polygraphing candidates and employees is a pragmatic strategy for improving the quality of new hires and maintaining security and safety in organizations such as the CIA and DOD, it’s not an infallible technology. Trained, skilled individuals may have the tools and techniques to help them evade detection through polygraph testing.

Evasion of deception detection is rare, very rare. A skilled polygraph technician is more than capable of weeding out the bad apples. However, there is a chance the individual could slip through the cracks. Research shows that polygraphs are 98% effective, but that means there’s a 2% margin of error.

Is it possible to add other strategies to polygraphing policies to enhance the efficacy of these procedures? Perhaps. Computer Voice Stress Analysis (CVSA) offers employers a complimentary method of polygraph testing to enhance effectiveness and improve results associated with the screening process.

This post unpacks CVSA technology and how to implement it alongside polygraph policies for an airtight screening process for candidates and employees.


Polygraphs and CVSA Tech

The polygraph is the de facto standard in lie detection. It’s effective at uncovering deception, and with good reason. This technology is over 150 years in the making. It started with pulse rate analysis in the 1870s, leading to the development of the first polygraph device in the 1920s.

The last century of evolution in polygraph saw technicians integrate computer technology into polygraph devices. The power of software and algorithms changed the game, making polygraphs more accurate than ever. Today’s machines are almost unbeatable. However, there is still a small margin of error involved.

To enhance the efficacy of polygraphs, law enforcement agencies may use Computer Voice Stress Analysis (CVSA) alongside polygraph exams to improve results. It’s common for law enforcement agencies to use polygraph and CVSA technology in investigations, interrogation techniques, and in parole programs. Recently, a US court ruled that CVSA technology may be used for post-release supervision of sex offenders.


The Different Types of CVSA Technology

Like polygraph technology, manufacturing and R&D firms are involved in progressing and developing CVSA tech. Today’s CVSA technology integrates with software and runs on laptops and mobile devices. This software is so effective that it provides accurate results in face-to-face and phone calls.

CVSA software and apps rely on a microphone connected to a laptop or mobile device. The microphone sends signals to the software or app, where an algorithm analyzes changes in the subject’s voice frequency when responding to questions. The software or app provides a score for the test at the end of the session. It allows examiners to see if the subject is deceptive in their answers.

The use of CVSA in criminal investigations and proceedings is only the tip of the iceberg for this technology. CVSA can flag deceptive behavior in many other screening procedures in government institutions like homeland security, DOD, airport security, border control, and others.

It also has a place in the private sector for enhancing the efficacy of pre-employment screening and employee testing in financial institutions, insurance providers, pharmaceutical manufacturing and distribution, and high-value asset management. CVSA provides value to employers wherever deception may present a problem.


AVATAR is a screening system developed by The Department of Homeland Security’s National Center for Border Security and Immigration at the University of Arizona. The Automated Virtual Agent for Truth Assessments in Real-Time (AVATAR) flags strange or suspicious behavior, warranting further investigation by agents in the field.

This technology is an automated system conducting interviews in screening contexts, such as personnel reinvestigations, trusted traveler application programs, visa application reviews, or other related scenarios where deception is a concern. The initial field test of AVATAR occurred in late 2013 in Romania.

AVATAR utilizes a non-invasive sensor system tracking body movement, pupil dilation, and changes in vocal tone and pitch to identify irregular or suspicious behavior, warranting further investigation. AVATAR is successful in several simulated scenarios involving exercises with US Border Patrol.

Beyond Verbal Communications

This Israeli firm identifies as an emotional analytics company. It’s another organization implementing voice recognition technology for various applications, such as monitoring airline pilots and call center interactions.

Beyond Verbal offers a cloud-based licensed software service. Third-party developers connect to its SDK and API, using the technology in several fields.


Nemesysco is an Israeli firm specializing in CVSA solutions. Its proprietary software utilizes “Layered Voice Analysis” (LVA) for identifying cognitive processes, stress levels, and emotional reactions in a subject’s voice.

Nemesysco states that LVA differs from conventional CVSA technologies because it utilizes unique technology for detecting “brain activity tracing” using the subject’s voice as the assessment medium. LVA analyzes a broad spectrum of factors detecting involuntary changes in speech waveforms and brain activity, classifying them as excitement, stress, and deception.


What are the Advantages of Voice Stress Analysis for Law Enforcement Applications?

Dr. Patrick Flood and Dr. Hugh Wilson Ridelhuber submitted a policy review to the Law Enforcement Executive Forum in August 2002. Its purpose was to demonstrate the efficacy and validity of CVSA in Law enforcement applications.

In 2002, law enforcement was reeling from the wake of the 9/11 attacks, looking for means to improve security and investigative techniques. In previous reviews, CVSA tech received negative scores from polygraph professionals. However, Flood and Ridelhuber were determined to rectify its reputation by introducing the law enforcement community to the history, science, and benefits of implementing CVSA tech in law enforcement applications.


Exploring the History and Theory Behind CVSA

Flood and Ridelhuber’s policy review addresses the theory and history behind CVSA. The initial use of the technology occurred in 1971 by Olaf Lippold, the originator of “muscle micro-tremor” analysis. His experiment observed involuntary vibrations in arm muscles are detected in relaxed subjects, but these tremors go away when the examinee is under stress. It’s similar to the principle applied in CVSA examinations.

The tech detects micro-tremors in the throat and larynx of subjects when speaking in a relaxed state. However, as in Lippold’s experiments, these tremors disappear when the examinee is stressed. The study’s results showed the need for developing a device to track this behavior in test subjects involved in deception detection.

Dektor Counterintelligence and Security, Inc. introduced the first CVSA device in 1972. The “Psychological Stress Evaluator” (PSE) showed initial success but failed to gain mass adoption across the polygraph community.

Two decades later, in 1988, CVSA tech arrived to replace the outdated PSE device. Initially marketed as an alternative to a polygraph, many law enforcement agencies decided to replace their polygraph systems with CVSA devices. By 1994, more law enforcement agencies relied on CVSA than polygraphs. By 2002, over 1,300 law enforcement agencies were using CVSA.


The Advantages of CVSA for Law Enforcement

Flood and Ridelhuber released their updated review of CVSA technology in 2002, listing the following key benefits of using it over polygraph tech.


Optimal Results

CVSA doesn’t create the same air of anxiety in the examination room. The subject isn’t hooked up to sensors and blood pressure cuffs, making them feel more relaxed. The subject wears a small microphone clipped to their jacket or shift cuff, and that’s it.

This calmer subject environment makes it easier for examiners to identify stressed responses in the subject. The structure of CVSA exams also increases the likelihood of the examinee making a confession because the test subject sees their results on a chart, and it’s easy for them to see the results pointing toward deceptive answers.

Reliability & Versatility

CVSA technology detects involuntary changes in vocal cord movement, which the subject cannot control. While there are countermeasures that subjects can employ against polygraphs, there are no known countermeasures available for CVSA examinations.

CVSA technology is implemented in standard questioning procedures and covert operations. Like polygraph exams, the examiner records CVSA results and analyzes them later. Floor and Ridelhuber asserted this strategy are ideal for use in counter-terrorism questioning.

Today, CVSA is under review in law enforcement for use alongside police body cameras for detecting deception in encounters with suspects in the field.

Expert Examiners

Flood and Ridelhuber note that CVSA tech is very reliable, with examiners employed by law enforcement agencies. Due to their law enforcement background, examiners have the foundational knowledge of legal, effective questioning techniques. In contrast, polygraph examiners require a bachelor’s degree and no previous training or experience in law enforcement techniques.

Cost Savings

CVSA offers law enforcement departments and agencies the chance to reduce operating costs. This factor is important in an era where departments try to slash budgets wherever possible. Implementing CVSA tech lowers costs without compromising investigative quality.

CVSA systems also require less training time to use the device and software correctly. Therefore, departments don’t have to send their staff away for long training seminars. As a practical example of CVSA technology saving law enforcement departments money, the Orange County Sheriff’s Office saved approximately $110,000 on polygraph costs after adopting CVSA in 2001.


Evaluating Research on CVSA Technology

When Flood and Ridelhuber published their 2002 policy review, the Department of Defense Polygraph Institute (DoDPI) questioned the validity of CVSA technology in studies they released in the same year. Flood and Ridelhuber argued the DoDPI’s testing environment didn’t provide an effective model of real-world testing.

Specifically, the DoDPI’s testing results didn’t create a “high-stakes” environment where subjects understood there would be severe consequences for lying and failing the test. A 1973 study by Gordon H. Barland showed subjects must undergo a specific stress threshold before they experience changes in the voice that CVSA technology can interpret as deceptive behavior. According to Flood and Ridelhuber, the DoDPIs failed to meet this standard in their simulated environment.

Flood and Ridelhuber also noted that the examiner must undergo a six-day training period for CVSA tech to be effective. The DoDPI’s study used a poorly trained examiner in the study, using the same questioning format as used in polygraph examinations.

Due to changes in baseline standards for CVSA testing in the DoPPIs study, the experiment was doomed to fail from the start. As a result, Flood and Ridelhuber argued the study results should be deemed invalid and disregarded from the record.

Therefore, there’s no scientific evidence disproving the efficacy of CVSA technology. In contrast, the Chapman study research demonstrates the reliability of CVSA technology in detecting deceptive behavior in test subjects.


In Closing – What are the Applications for CVSA Technology?

The conclusion of the 2002 policy review by Flood and Ridelhuber highlights a range of applications for CVSA technology. From pre-employment screening to counter-terrorism measures, there are dozens of uses where CVSA proves effective at detecting deception.

Should CVSA experience widespread adoption in the industry, it could act as a deterrent for terrorist activities and criminals looking to plan crimes. CVSA greatly increases the likelihood of criminals being caught before they can carry out the act, provided they are apprehended by authorities before the planned event.

In addition, researchers include local and state law enforcement agencies, who have adopted CVSA technology as their standard in deception detection. In the last 20+ years since the publication of Flood and Ridelhuber’s policy review, CVSA has grown from strength to strength and remains a valuable tool that many law enforcement agencies and private sector employers use alongside polygraphs for effective deception detection.