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Lie detectors are used commonly by police departments throughoutthe United States as a tool to help detect deception based onbodily responses to stress , such as pulse and breathing rate, that are relayed by sensorsattached to the suspect,. However, sensitivity is limited and thesensors can be fooled by simple techniques well described on avariety of websites. But by evaluating the acoustical properties of the human voice, aresearch team at the University of Florida, Gainesville, isexpanding the scientific understanding of the physics of vocalstress insight that might one day be used to improve the detectionof deception. The research team confirmed that the human voicechanges in systematic and perceptible ways under carefullymeasured, significant stress levels. One early surprise finding isthat men and women respond differently to the same stressors. Thegroup will present its work at the 162nd Meeting of the AcousticalSociety of America in San Diego on Nov. 2, 2011. "In male subjects, higher degrees of physiological arousal wereunder-reported what you might call a 'tough guy' response,"explains lead researcher, James Harnsberger, Ph.D., a speechscientist in the Department of Linguistics. The idea to test forgender difference was not part of the original study design. Agraduate student on the project, Christian Betzen, suggestedanalyzing separately the gender categories for the four stressmetrics used in the study - two physical and two self-reporting."The results were a surprise. We had expected that higher stressorswould prompt both increased physiological response and increasedself-reported stress levels in all test subjects fairly uniformlyfor both men and women," Dr. Harnsberger explains. One earlyconclusion these data suggest is that acoustic analyses shouldinclude gender in the study design. In the study, the Florida team enrolled study subjects fromcommunity or religious groups who were considered "committed" thatis, strongly affiliated with a group identity. The study subjectswere audio-visually recorded while coached by the researchers tovocalize both truthful and deceptive statements with the threatfrom the researchers that the recordings would be shown to fellowcommunity members for judgment. In some conditions, stress was alsoinduced by the administration of electric shock at levelscalibrated by the individual volunteer. Other stress responses weremeasured by pulse rate, skin conductance level (due to sweat),pulse rate, and two self-report scales of perceived discomfort. Over time, studies such as this hold promise for improving avariety of speech analysis systems in a range of settings from liedetectors to computerized voice recognition. This is because theacoustic properties of stressed speech overlap with acousticproperties of speech that are dependent on such variables as thespeaker's unique identity, his emotional state, and the words heproduces. The paper 3aSCb44, "Talker and gender effects in induced,simulated, and perceived stress in speech," will be presentedWednesday morning, Nov. 2. Additional References Citations. We are high quality suppliers, our products such as China Electric Chain Hoist , Wire Rope Hoist Manufacturer for oversee buyer. To know more, please visits Wire Rope Electric Hoist.
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