What it is:
The VSA 15 is an electronic Voice Stress Analyzer.

What it does:
It measures the human voice for stress, helping to indicate if a person is lying or telling the truth.

How it works:
The VSA 15 has 2 methods of testing for Truth. Overt & Covert test examinations.

Overt Testing
During an interview or interrogation, a person (examiner) will ask the suspect (person being questioned) to answer questions. The examiner will use the VSA 15 to measure "true" answers to questions, establishing a baseline of truth values.

The examiner then can use the VSA 15 to take readings on the answers of other questions that may or may not be true. After reviewing the measured results, the examiner can determine the similar or different truth values, indicating truth or lies.

Covert Testing
The VSA 15 can test over a phone line without the subject actually knowing, thanks to a voice processor fed directly into a built-in recorder. This processor will transfer the voice tones, and the recorder will then be able to reply the answers into the analyzer for truth verification.