Voice stress analysis (VSA) refers to the use of devices that purportedly detect the existence of truth, deception, and/or stress from voice and speech. Manufacturers of VSA devices note that their low cost, short training and high accuracy render the VSA an invaluable tool for law enforcement and military personnel.

However, substantiation of VSA's utility proided by these companies has consisted of only single-case ecamples and/or anecdotes without any scientific evidence regarding their efficacy. Research regarding the accuracy and efficacy of VSA has, to date, been mixed at best.

Although some studies have shown VSA technologies to be sensitive to stress, none of the studies found these technologies to provide reliable indicators of deception or truthfulness.