Voice Stress - Criticism

Criticism

Voice Stress Analysis (VSA) remains a controversial lie detection technology. It was described as pseudoscientific. While there is a wealth of scientific basis for the underlying theory of "microtremors," this data is based predominantly upon research on skeletal muscle (i.e. calf, finger). This data has been extrapolated to the muscles that control phonation.

Federally funded research via the American Polygraph Association in the United States showed "little validity" in the technique.

Air Force Research Laboratory conducted validation studies into VSA and concluded that mainstream VSA were useful in focusing investigations and obtaining confessions by convincing suspects that they cannot deceive the machine.

There is tension between the voice stress analysis community and the polygraph community, due in the main to the fact that the polygraph is heavily regulated and has been subject to numerous detailed, contentious scientific studies, while voice stress analysis is largely unregulated. However, there are few studies which show VSA results to be even slightly better than chance.

In Anders Eriksson and Francisco Lacerda's article "Charlatanry in forensic speech science: A problem to be taken seriously" voice stress analysis is described as charlatanry, and that analysis of studies shows that these methods perform at chance levels. They argue that "there are serious ethical and security reasons to demand that responsible authorities and institutions should not get involved in such practices." Not surprisingly, this article meet its own criticisms from manufacturers of voice stress analysis machines. Due to the controversy, the International Association of Forensic Linguists' peer-reviewed journal International Journal of Speech, Language and the Law withdraw the article. However, there have no subsequent studies that refute the findings contained within that article.