Are there different types of “lie detectors?
There are several types of polygraphs on the market today. Each instrument records the same basic psychophysiological data as described above. The actual recording may be made using ink and paper or by computer. There are those who claim to detect lying using “voice stress.” It is important to know, every scientific research project assessing the “voice stress” technology has found the test to be accurate between 47% and 52% of the time. Voice Stress is not used by any of our National Security Agencies including, the CIA, NSA, and FBI, etc. Substantial research has been done by the Department of Defense to access the reliability of “voice stress.” No Department of Defense Agency uses “voice stress.” The scientific community does not recognize “voice stress” as a reliable way to detect truth or deception. In 1989, the Congress prohibited businesses from using “voice stress” to test applicants or employees. Substantial penalties exist for violations of the ban.
