Me: Fuckin' spiffy.
(fast forward 3 hours, during which I get home from work and eat dinner)
Dug into the dryer and found that the cause of the noise was a piece of crude felt about 3" square, which had flipped up into the fan and was thus being vibrated at some appreciable frequency, making the howling noise. After a bad half hour painstakingly cleaning lint out of the blower assembly, it's nice and quiet again.
"Crude felt": the lint screen on a dryer is not perfect. Some fibers get through it, and since they're damp will stick to the first thing they hit. In this case, the bottom of the duct that directs air out of the dryer. The fibers are oriented randomly, and over time enough of them build up to make a sort of crappy felt.
...but if I was one of those television people who don't know shit about anything, I'd have had to pay a repairman $200 to fix this thing. Instead, I'm the "competent man" (who, according to SJWs, doesn't actually exist) who can take apart a dryer and put it back together again and have it work better than it did.
* * *
Well, AV is moving along.
* * *