Polygraph vs. Voice Stress
While polygraph examinations have been developed over the course of one hundred years and have shown consistent accuracy in scientific research, recent innovations have attempted to use voice stress analysis for the same purpose. However, studies have been unable to prove accuracy or reliability with regard to voice stress technology.
In the position statement of the American Polygraph Association, President Richard W. Keifer states, "Current scientific evidence establishes the polygraph as the most accurate means of detecting deception. Recently there have been claims made that voice stress analysis is an accurate means of detecting deception. There is no independent research supporting the assertion that voice stress analysis is an accurate means of detecting deception. The APA does not endorse the use of voice stress analysis to determine or detect deception."
The Department of Defense Polygraph Institute makes the following conclusions in their voice stress analysis position statement:
- To date, we have found no credible evidence in information furnished by the manufacturers [of voice stress analysis equipment], the scientific literature, or in our own research, that voice stress analysis is an effective investigative tool for determining deception.
- A very few studies have found that voice stress analysis worked better than chance at detecting deception. Unfortunately, these results are not consistent, nor are the reported accuracies nearly as good as those normally reported for the polygraph.
- The preponderance of evidence indicates the polygraph is far more accurate at detecting deception than is voice stress analysis. No Department of Defense agency uses any form of voice stress analysis for investigative purposes."
The position statement of the American Association of Police Polygraphists states, " The AAPP has found no scientific studies or independent research which support voice stress analysis as a method of discriminating between truth and deception. Until voice stress analysis is supported by scientific research that conclusively demonstrates its validity and reliability, and American Association of Police Polygraphists will not endorse the use of such equipment in the law enforcement community." It also identifies polygraph as "the only deception detection device which has the scientific support and has earned judicial acceptance for expert testimony [in court proceedings]."
Source: American Polygraph Association