he Air Force Research Laboratory (AFRL) has been asked by the National Insti tute of Justice to investigate voice stress analysis (VSA) technology and evaluateits effectiveness for both military and law enforcement applications. Tis technology
has been marked as commercially available in computer based form, and marketed as
being capable of measuring stress and, in some systems, deception. Tis technology
is reported to be easier to use, less invasive and less constrained in its operation than
standard polygraph technology. Tis study has found the VSA technology can identify stress better than chance with performance approaching that of current polygraph
systems. However, it is not a technology that is mature enough to be used in a court of
law. We also found that experience and training improve the accuracy than less trained
individuals. Lastly, we explored how this technology may become an effective interrogation tool, when combined with polygraph technology. Tis article contains information and results of a primary work done to show how the stress changes for Mel
Frequency Cepstral Coefcient features can be detected through FFT signal processing when a person is under psychological pressure. Te principal purpose is to obtain
a tool that could help the accused to prove their innocence in an offense or a crime