Friday, February 22, 2008

Language in Court

Here is the abstract for a rather interesting linguistics talk next week by our new prof from Australia:

Native Title is a form of radical land title found by the High Court of Australia to have existed at the time of the European invasion of Australia. In order to establish a successful claim on land that has not had any other kind of title, Native Title claimants have to establish that they have continuity with the occupants of the claimed area going back to the first settlement by non-Indigenous Australians. While a range of evidence is amassed in this process, I will discuss the use of linguistics in showing continuity with particular reference to two cases (Daniel v Western Australia and Bennell v Western Australia) in which I was employed by the claimants as a linguistic expert witness. Comparison of early texts in the language and more recent usage is one method used to show continuity, but there are issues of what constitutes 'same' and 'different' for the purposes of a legal argument. In one case we actually have hundreds of early sources, and dealing with this mass of information is a challenge for lexical comparisons.

Testifying in court to establish a land claim is not a use of linguistics one usually things about, but in fact there's an entire sub-field of linguistics called "forensic linguistics". It handles all sorts of language related issues in the justice system, from the use of language in court to phonetic analysis of evidence. When you hear that the CIA is analyzing an audio tape to see if it's really Osama on the tape, those are forensic linguists at work. Humans create sounds, particularly vowels, by reshaping our vocal tract (with our tongue and lips) and dividing it up into different resonant tubes. We all have different length vocal tubes, different size vocal cords, and even slightly different shape skulls. This all makes the sound vibrate in slightly different ways physically and identifies your speech as yours.

To take a very basic difference, you can divide the vocal tract from your voice box to your lips into two tubes. One is vertical and leads from the voice box up to where your uvula hangs down (basically your throat above the voice box); the other is horizontal and goes from the back of the throat to the lips. These two tubes are more even in women, than they are in men. Men have slightly longer back tubes (I believe). Even apart from the overall pitch difference, this is one reason a woman sounds like a woman and a man a man. If a man raises his voice to be about the same pitch as a woman, he sounds like a man who's raised his pitch. To actually sounds like the other gender, you'd have to change the complete size of your vocal tract, which is not easy to do. (Of course, there are individual differences; these are generalities about the sexes.)

Maybe if this professor thing doesn't work out, I can think of this stuff as a back-up. See you on CSI-Real Stories next season.

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