Voice Stress
Voice Stress Analysis (VSA) technology is said to record psychophysiological stress responses that are present in human voice, when a person suffers psychological stress in response to a stimulus (question) and where the consequences may be dire for the subject being 'tested'.
In the Detection Of Deception (DOD) scenario, the voice-stress produced in response to a Relevant Question ("did you do it?") is referred to as psychological stress or 'deceptive stress'. However, it is not possible to cleanly separate the excitation signal into components due to emotion and those due to deception. Thus no DOD technology can detect a lie or truth unequivocally, but only whether a speaker is experiencing stress. For example, a suspect under questioning would also display natural stress even if he were not guilty.
The technique's accuracy remains debated. There are no independent research studies that support the use of VSA as a reliable lie detection technology, whilst there are numerous studies that dispute its reliability.
In civil court testimony, the CVSA founder, Mr. Charles Humble, testified that "NITV acknowledges that the CVSA is not capable of lie detection and specifically cautions its users regarding proper use of the device."
Air Force Research Laboratory (Haddad et al.) conducted validation studies into VSA and concluded that mainstream VSA (Diogenes and CVSA) as well as polygraph tests are useful in helping trained operators in obtaining confessions by convincing the subject that they cannot deceive the device. As such, it is considered a useful interrogation tool.
Read more about Voice Stress: Criticism, VSA Vs LVA, Principle and Origins, Vendors, Applications, Methodology and Accuracy, Notable Examples of Use
Famous quotes containing the words voice and/or stress:
“Reason is a faculty far larger than mere objective force. When either the political or the scientific discourse announces itself as the voice of reason, it is playing God, and should be spanked and stood in the corner.”
—Ursula K. Le Guin (b. 1929)
“While ... we cannot and must not hide our concern for grave world dangers, and while, at the same time, we cannot build walls around ourselves and hide our heads in the sand, we must go forward with all our strength to stress and to strive for international peace. In this effort America must and will protect herself.”
—Franklin D. Roosevelt (1882–1945)