北师大版高中英语模块11--Unit33(3)-3
[00:03.63]Cheaper and faster than a polygraph,
[00:06.18]the voice stress analyser,
[00:08.31]or VSA is based on the premise
[00:10.85]that our voice changes when we are under stress
[00:13.90]-when we're lying for example.
[00:15.91]The VSA detects the changes,
[00:18.49]and will work on a telephone,
[00:20.29]tape recording or from the next room via
[00:23.30]a wireless mic or bug.
[00:25.35]The analyser monitors the subject's
[00:27.56]voice patterns and inflections,
[00:29.99]and electronically evaluates their relative
[00:32.81]stress patterns to determine
[00:34.82]if they are lying or not.
[00:36.97]Now you can even buy a "Truth Phone",
[00:39.94]so when your friend rigns to say they're sick
[00:42.57]and can't do their share of your group project,
[00:45.52]you can immediately know
[00:47.29]if it's true or not!
[00:48.93]Research indicates this technology
[00:51.11]is not very precise at picking up
[00:53.46]deceitfulness however.
[00:56.26]4 Hesitation
[00:58.39]The period of time between the last word
[01:00.71]of an investigator's question
[01:02.59]and the first word of the subject's
[01:05.13]response is know as "Response latency".
[01:07.82]Research tells us that the average response
[01:10.44]latency for subjects who are telling the truth
[01:13.29]is 0.5 seconds...
[01:15.87]whereas the average latency for liars
[01:18.60]is 1.5 seconds.
[01:18.60]
