Polygraph Glossary Technique

voice stress analysis

Definition

Voice stress analysis (VSA) encompasses technologies claiming to detect deception through vocal signal analysis, typically in the 8–10 Hz microtremor range. Devices include the CVSA, LVA, and PSE. No independent scientific assessment has validated any VSA device for credibility assessment. The U....

What Is Voice Stress Analysis?

Voice stress analysis (VSA) encompasses technologies claiming to detect deception through vocal signal analysis, typically in the 8–10 Hz microtremor range. Devices include the CVSA, LVA, and PSE. No independent scientific assessment has validated any VSA device for credibility assessment. The U.S. Department of Defense prohibits their use.

Historical and Modern Context

The evolution of polygraph instrumentation — from early mechanical devices to modern digital systems — reflects the broader advancement of the field from subjective interpretation to validated, structured test data analysis. Modern instruments from manufacturers such as Lafayette, Limestone, and Stoelting incorporate multiple measurement channels, digital recording, and computerised scoring capabilities.

Professional Context

This concept forms part of the knowledge base expected of qualified forensic psychophysiologists. Training at APA-accredited schools covers the theoretical foundations, practical applications, and research evidence underlying all aspects of polygraph methodology. Ongoing continuing education ensures practitioners stay current with developments in the field.

Cross-references

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