In 1957, University College London researcher Olof Lippold discovered that all muscles in the human body, including the vocal chords, vibrate within the frequency range of 8-12 Hz range. This vibration, of course, occurs as muscles tighten and relax.
Lippold charted these vibrations by using electrodes applied to the extensor muscle of the middle finger. Electrical activity generated by muscles was then recorded on an Electromyograph (EMG), a medical technology designed for evaluating and noting this type of activity.
Several years later, in 1972, three retired U.S. military officers—Allan D. Bell Jr., Wilson H. Ford, and Charles R. McQuiston—formed the company Dektor Counterintelligence and Security, Inc.
Shortly after, the men filed a patent for an invention—the Psychological Stress Evaluator (PSE)— that could analyze voice recordings. It was the world’s first Voice Stress Analyzer and it was based Lippold’s work. It was the ultimate in lie-detecting technology.
Cherry Tree Mystery Solved – George Washington Confesses!
Today, Computer Voice Stress Analyzer (CVSA) technology is capable of detecting even inaudible voice stress in subjects/suspects who are undergoing questioning by police investigators.
He Didn’t Do It … Yeah, Right!
CVSA technology focuses on the inaudible and stress-induced aspects of the voice—muscle micro-tremors.
Many investigators and department officials find that voice stress analysis is more reliable than polygraph examinations, and the voice stress system is less expensive and requires far less training time.
How Does it Work?
To see how this process works, please click to watch the video below. Then see how quickly the hero of your story extracts a confession from the bad guy.
And the cop to the crook …
“Ain’t that what you said?