The National Institute of Corrections has published a research study on voice stress analysis (VSA) conducted by the Oklahoma Department of Mental Health and Substance Abuse Services with support from the National Institute of Justice. From the abstract (emphasis added):
…The goal of this study was to test the validity and reliability of two popular VSA programs (LVA [Layered Voice Analysis] and CVSA [Computer Voice Stress Analyzer]) in a “real world” setting. Questions about recent drug use were asked of a random sample of arrestees in a county jail. Their responses and the VSA output were compared to a subsequent urinalysis to determine if the VSA programs could detect deception. Both VSA programs show poor validity – neither program efficiently determined who was being deceptive about recent drug use. The programs were not able to detect deception at a rate any better than chance….
The 128-page report, “Assessing the Validity of Voice Stress Analysis Tools in a Jail Setting” by Kelly R. Damphousse, Laura Pointon, Deidre Upchurch, and Rebecca K. Moore, dated 31 March 2007, may be downloaded from AntiPolygraph.org here (2.1 mb PDF).