Yeah, you do.
I was dying to try this thing out. Truth is, I was skeptical that this app would be anything more than a novelty item.
But I had a serious moral dilemma on my hands. What kind of person interrogates his wife and purposely tries to make her cough up lies just so he can test out an app for a blog post?
Me. So I was off, for 15 minutes, asking her question after question, spanning a wide spectrum, none of which I'll get into. Very little of my prodding resulted in anything more than a blip on the Lie Graph. None of my deep, life-altering questions drew a response that warranted much more than a light yellow reading on the Lie Meter. A few other quick tests with other people did show a wider range of results.
The Agile Lie Detector uses voice stress analysis, a somewhat controversial alternative to the traditional polygraph test, to determine whether or not someone is lying. The bad side of this is that it's not considered as accurate as hooking someone up to a machine that measures more than one physiological response, like breathing and pulse. The good side is -- theoretically anyway -- you don't need to be in the same room as the person you are trying to test. In fact, it's possible to analyze speech through speakers, assuming the quality of those speakers is high enough.
To play with this a bit, I searched for video on YouTube that showed people obviously lying (think Clinton's denial of his canoodling with Monica Lewinsky) or obviously under stress (think Sarah Palin talking to Katie Couric). The results of holding my iPhone up to the speaker as these and other videos played showed, in a most unscientific and probably flawed way, a difference, however slight, versus when people not under stress spoke. The very cool part of the application is that it gives you results in real time, so you can see from moment to moment when someone is getting a bit nervous. Theoretically.
If I were the feds, I wouldn't be shipping off a crate of iPhones (liePhones?) to Gitmo quite yet. This application is filed under the Entertainment category in the App Store for a reason. It shouldn't be relied on in serious situations. You know, like asking your wife if she really, truly thinks you look good in that new jacket of yours. However, if voice stress analysis is your bag, definitely give this app a try. I won't lie though. It's a tad pricey.