an answer I require

In this entry I asked whether the chirping birdies that fly around cartoon characters' heads when they bump their noggins reflected something real or are just a convention of cartoon storytelling.

The answers I got ran the gamut, from yes, "the flash of tiny lights, the dizziness, the eeee! of tinnitus," to so emphatically nothing of the kind that they can't imagine that the convention reflects anything real at all.

That confirms what I've always suspected, that there's a physiological variation among humans here. Because my own response is close to vgqn in the middle: I "see stars" - points of light that drift around and vanish, caused by pressure on the optic nerve - but there's no aural effect. So I wondered where the chirping birds come from, while occasionally hearing remarks in response to the cartoons suggesting that the speaker thought the whole thing imaginary.

This was one of those questions that's drifted in the back of my mind for many years, possibly since childhood. What brought it to mind when I was sitting at the computer ready to write an LJ post was an entry at the Comics Curmudgeon mentioning how odd it is for a comic strip character to talk about her shoes when "we almost never get to see her below the solar plexus," and I was wondering, what exactly is the solar plexus anyway? And when I looked it up, I found references to the phenomenon of "getting the wind knocked out of you," which I'd always thought was just a phrase for the oof of being hit in the stomach but apparently is more than that. And that made me think of my old question of "seeing stars" and the chirping birds.

MRI

It stands for "magnetic resonance imaging." I knew that.

What I had not known is what the machines are like, having never been near one before. But I have now. I was not in the machine being imaged by it, but I was seated in the scanning room while it was operating, having first, by instruction of the attendant personnel, taken the precautions of inserting the expand-into-place plastic earplugs, and removing all trace of potentially magnet-friendly metal from my person.

The machine looks something like an oversized 1950s canister vacuum cleaner, and when it's operating it makes noise. Very loud noise, but intermittent, not continuous. It sounds like a cross between a Dalek, a truck in reverse, and a malfunctioning washing machine. Occasionally it resembled the music of some hyper-modernist composers, possibly from Darmstadt, whose names I have thankfully forgotten.

I am not generally subject to headaches, but this was almost enough to give me one.