Bloody noise

Master and I live in a building with thin walls, to say the least. At night I can hear people talking in the room below me in normal conversations - they aren't even trying to be loud! So, naturally, we have to be very quiet when we're playing.

I think it's easier for him; he usually doesn't make a lot of noise during sex, and he doesn't have to repress squeals of pain like I do (though he does have to watch out about not making to much of a smacking noise when he spanks me). But this makes me wonder about the noises we make when we're hurt.

There are different kinds of noises for different kinds of pain. When I have cramps, I usually don't make any noise except for an occasional low, drawn-out groan. When my muscles are sore from working out, my groans are louder and shorter. There's the classic "ouch!" when something pricks our skin, which can evolve into a full-blooded scream when the pain is extreme, like when my brother almost had his thumb cut off. It seems that the more painful something is, the louder our protestations.

And then there are the noises I make when Master and I play. I don't make those noises any other time; they're a kind of groan-gasp-squeal, usually muffled by either biting on a pillow or force of willpower alone. Master calls them "whimpers," which I suppose fits. A whimper can be in suffering, in desire, in many things.

I wonder why we make noises when we experience pain. We're far from the only species that does it; a cat will screech, a dog yelps, monkeys scream, and so on. Is there some evolutionary advantage? Does the sudden loud vocalization possibly frighten off whatever caused the pain? Does it signal to any fellow beings, "I'm in trouble! Run/help me!"

I dunno. I'm no biologist, hah!