POST: "Voice stress analysis challenges," by Justin J. McShane, posted on "The truth about forensic science," on December 19, 2013.
GIST: "The speculation behind how Voice Stress Analysis (VSA) works is based upon the following premise: liars experience more psychological stress when lying than truth tellers do when they tell the truth. The notion is that this psychological stress results in minor changes in the blood circulation, which subsequently influences various characteristics of the voice. This is where they employ an instrument known as a Psychological Stress Evaluator and use microphones attached to a computer to detect and display intensity, frequency, pitch, harmonics or (my favorite) microtremors. It is used in the workplace and even in some police investigations today including the recent high-profile case of George Zimmerman’s shooting of Trayvon Martin. There is absolutely no empirical validity to any of the above assertions by the VSA community. None.........The National Research Council in 2003 concluded that “although proponents of voice stress analysis claim high levels of accuracy, empirical research on the validity of the technique has been far from encouraging.” The US Department of Defense Polygraph Institute conducted a controlled study and found it to be inferior to the polygraph and slightly above random chance in the detection of lies.So, it is scientific junk. Why does it persist as an investigative tool? Beats me.
The entire post can be found at:
http://www.thetruthaboutforensicscience.com/voice-stress-analysis-challenges/
PUBLISHER'S NOTE:
Dear Reader. Keep your eye on the Charles Smith Blog. We are following this case.
I have added a search box for content in this blog which now encompasses several thousand posts. The search box is located near the bottom of the screen just above the list of links. I am confident that this powerful search tool provided by "Blogger" will help our readers and myself get more out of the site.
The Toronto Star, my previous employer for more than twenty incredible years, has put considerable effort into exposing the harm caused by Dr. Charles Smith and his protectors - and into pushing for reform of Ontario's forensic pediatric pathology system. The Star has a "topic" section which focuses on recent stories related to Dr. Charles Smith. It can be found at:
http://www.thestar.com/topic/
Information on "The Charles Smith Blog Award"- and its nomination process - can be found at:
http://smithforensic.blogspot.ca/2013/12/the-charles-smith-award-presented-to_28.html
I look forward to hearing from readers at:
hlevy15@gmail.com;
