Tuesday, February 15, 2011

Solving Cases with Technology: Voice Stress Analysis

Voice stress analysis more commonly known as VSA is a very effective way to determine if someone is lying. It is designed to measure the changes caused by how the body reacts to stressful situations. The foundation of VSA technology is that a person’s voice emits detectable fluctuation in both AM, amplitude modulation, and FM, frequency modulation, frequencies called microtremors. When you listen to a person speaking, you hear the AM which rides atop the FM, which is undetectable to the human ear. Under the stress created from a deceptive response there is a reduction in the FM frequencies causing the microtremors to increase. It is an involuntary autonomic response detectable with a microphone and a computer running the proper software. The skilled examiner then analyzes the person’s voice patterns looking for these frequency discrepancies. Since this the change in frequencies is an involuntary response there are no known counter measures. A person cannot manipulate his voice frequencies the way he may be able to manipulate blood pressure, breathing, and skin response. 

When compared with a polygraph, the VSA technology is easier to use, faster to administer, less stressful, cheaper, and 98% accurate. VSA works in any language whether the subject is face to face or on the phone. Drugs, alcohol, and medical conditions do not affect the tests. Voice recordings that are years old can be used to solve cold cases. This test is less stressful for the subject than a polygraph test which makes VSA more accurate. When compared with a polygraph, the VSA technology is easier to use, faster to administer, less stressful, cheaper, and 98% accurate. A VSA test is more effective than a polygraph test because polygraph tests can’t analyze a recording while a VSA test can. Each test has the same admissibility in court.

6 comments:

Janelle said...

I thought that Jake gave a very though Summary of the article. He explains the processes that were used to detect deception in some one’s voice. I understand much better how the ear works. He also did a good job explaining How the actual machine worked. Even though it was very technical I understood the process. With each technical advance it becomes easier to interview suspects effectively and more criminals are caught and put away. I agree that this is very important to victims of any crime and to society at large. I also liked the way he told the pros of the new method as compared to the polygraph. Overall it was a very comprehensive summary and gave a clear picture of the article he read.
I did, however think that he could have had a better critic of the article. There was nothing on what he personally thought of the article or how it could have better. The other thing I thought was not as good as it could have been was when she explained why she found the article interesting that lacked any real substance or personal feeling. It really only included the pros of the method and the sentence was repeated twice. I was especially impressed by the fact that this will now allow them to get a 98 % accuracy reading, which is better than the traditional polygraph. I didn’t realize how accurate lie detectors could be.

Russell said...

Jake did a very good job summarizing this article. He described the voice stress analysis process very well. The machine works by detecting changes caused by how the body reacts to stressful situations. Through his description, he made it very easy for the reader to understand how the machine works and how it differs from the human ear. There are certain sound patterns that are undetectable to the human ear. This machine could play a vital role in solving future crimes. I liked how he compared it to the polygraph and described how the VSA test is much more accurate. Overall, Jake did an excellent job in discussing the key points of this article and how it can greatly benefit forensic scientists.
Jake could have offered some of his personal opinion and told us what he believes the significance of the VSA test is. He also didn't include what he liked or didn't like about the article. Jake could have also added why he chose this article and why he found it interesting. However, Jake did provided some great facts and made it clear to the reader how accurate this test can be.

Ivan said...

I believe Jake gave a very in depth summary of the article he chose. He described how It is designed to measure the changes caused by how the body reacts to stressful situations. Also how under the stress created from a deceptive response there is a reduction in the FM frequencies causing the micro tremors to increase. Finally, he did a good job explaining how the machine works and now I even haven an idea of how the ear works.

There were two things that he could have changed/included in the article. He did not put enough personal thought or feeling on the article he had read. Not much of a reflection. Second, I feel he should have made a separate paragraph where he could had included this personal reflection on his article so there could be more flow and organization in the writing.

What I thought was interesting and did not know before reading was that a VSA test is more effective than a polygraph test because polygraph tests can’t analyze a recording while a VSA test can. Also that each test has the same admissibility in court.

Kathleen Moriarty said...

I think Jake selected a great article that really impressed me. Voice analysis sounded complex to me at first, but Jake’s writing style made it easier for me to understand. I found it to be an interesting read because I found it very hard to put down once it grabbed my attention.
However, this article isn’t perfect. I noticed two flaws. First of all, I think Jake was a bit brief in the second paragraph. Second, I noticed a few typos. Did he spell the word “discrepancies” right? Anyway, I would like to see more evidence in order to prove that the Voice Stress Analysis (VSA) method is more effective than the polygraph (lie detector).
Finally, I would like to point out that I like the description of voice frequency and amplitude – absolutely fascinating. Since I don’t know much about this subject, I found it very interesting to learn from. That is all.

Devon said...

Jake does a really good job presenting this information about analyzing voice stress. There are a lot of complicated terms that are involved which are hard to follow; however, Jake does a great job keeping it easy to follow. I also like this article as a whole; he chose an interesting topic to read about. Also, I like how Jake presented all the important information and made it very clear as to what the article was talking about.
I think Jake could have added more of the names of people and organizations involved with this analysis. Like the DODPI and the previous inventors. I also would have liked to see three distinct paragraphs in his summary of the article.
Overall, I learned a lot from this article and it is interesting to see how it differs and builds off of the previous lie detector.

Alexandra said...

I thought that Jake wrote a well – written review on this article. The way that he described the various processes discussed I thought was great. He made the processes easy to understand. Jake also did a good just describing how the machine worked. With all the technological advances in the world now – a days, I think that eventually I will become fairly easy to figure out who the criminal is in a crime. All in all this review of the article was good.
However, I do believe that this review could have been written better. I thought that the review could have been discussing more on his thoughts of the article, which there seemed to be not enough on his personal thoughts on the essay. The review could have benefited more if he found the article to be interesting or if he thought anything about the recent technological advances. I was surprised that the machine will now allow a better reading than a traditional polygraph. Until now, I didn’t realize how sensitive and accurate lie detectors could be.