What I noticed is that president Obama seemed a mite testy in his weekly address for 10/1/2011 ("Fighting for the American Jobs Act"). This led me to ponder the phonetics of testiness, and of emotional expression in general. For this morning's Breakfast Experiment™ I thought I'd take up one small aspect of one dimension of this large topic, namely what happens to F0 ("fundamental frequency", commonly called "pitch") when you "raise your voice".He goes on to explain how differences in ambient background noise can make you raise your voice - if it's louder, you have to compensate. He decided to test a couple of speeches - one in August where he seemed calmer, and one in October, where he was noticeably louder. He found no difference in the level of background noise.
The difference is a fairly large one: an average pitch of 137.3 ±0.38 Hz on October 1, vs. an average of 106.6 ±0.31 Hz on August 6, for a proportional difference of about 29%. To avoid misunderstanding, let me repeat that there are lots of reasons for someone's pitch range to vary, so that this is not a reliable metric for physiological arousal. But when other things are held constant, it can be interpreted that way. And it's easier to quantify and compare than things like voice quality are.
I'd say the Mighty O is mighty rattled these days.
H/T Ace of Spades