The movie theater one is actually kind of interesting. There is a certain maximum audio power that a room can sustain before loosing fidelity. I think _all_ sound engineers know about this, but a projectionist with a volume knob probably does not.
Next time you're in a place where the audio is too loud for you to hear, try to listen carefully for a few seconds. You might discover that despite being too loud, it actually sounds bad, and reducing the volume would actually _improve_ the audio fidelity.
Next time you're in a place where the audio is too loud for you to hear, try to listen carefully for a few seconds. You might discover that despite being too loud, it actually sounds bad, and reducing the volume would actually _improve_ the audio fidelity.