How the lie detection system works

When a person talks, air is pushed from the lungs upwards, through the vocal cords that vibrate in a certain frequency. From there, the lips, tongue and teeth create the speech flow. Thought process and state of mind also play a large part in the flow of speech. In fact, any event that occurs in the brain (such as emotion, heightened concern, pain, etc.) is automatically reflected in the voice.

The feelings detected in the voice analysis reveal a psychological pattern that can indicate various situations in the subject's mind, including, stress, confusion, hesitation, and deception.

There is no set voice pattern or frequency for deceptive speech, because there are many types of lies, with many motives and many different people.

However the Truth produces a uniform appearance, where the typical thought process is flowing and uninterrupted. This pattern of truth is unique to each person, at any given time, and might change if the circumstances change.

One example of the superiority of VSA, if a friend in a café was asking someone about a topic, he may not feel he is being tested and so is more relaxed. Place that same person in a room with equipment and a dedicated interviewer; his brain will register a whole new set of values. He might be more alert, more stressed, less confident, more confused and so on.