英语时差：笑声里隐藏的声学

3 There's a lot more to laughter than you might imagine, as Don and Yael discuss in this Moment of Science. D: Let me hear you laugh, Yael.

Y: Ho, ho, ho.

D: That's not a real laugh. Researchers have found that in laughter we don't make articulated vowel-like sounds such as ho-ho and ha-ha and tee-hee. Laughter is mostly composed of more neutral sounds, something along the lines of huh-huh.

Y: Well what did you expect? You didn't give me anything to laugh about.

D: Fine. What's black and white and read all over?

Y: Ooh, let me see. A newspaper? You can't make me laugh with tired riddles, Don.

D: Forget it then. Let me just tell you what else I know about laughter. In men and women both, laughter reaches surprisingly high frequencies. Frequency is measured by the rate at which the vocal cords vibrate. We hear frequency as pitch. The laughter in some men can be as high as a soprano's high C, and in women, laughter can reach the pitch of an octave higher than that.

Y: That is pretty impressive. One might think we would shatter glass when we laughed, like opera singers do in cartoons.

D: What's more is not all laughter is voiced like this--meaning not all laughter involves the vocal cords. Of those who do voice their laughter, a majority of them are women. The resulting sounds are often song-like. Some people, however, make grunting and snorting noises in their laughter.

Y: Let me guess. Mostly men grunt and snort.

D: Well, that's true, but so what? We can't help it.

Y: You snort so much you're embarrassed about it? Now that might make me laugh. Let's hear you laugh, Don.

D: No. Leave me alone.