[Gametes]

My dad's sunflower iMac will have a low internal beep if you let it sit for awhile and then use it. I'm inclined to think it's the DVD burner or the hard drive waking up from "sleep".
Is this it? Can the DVD-drive make its own beep?

It's really annoying, as it's always accompanied by a 2-second pause while the computer gets up to speed.

[Eriamjh]

That's the hard drive going from sleep to spin-up.
Check the Energy Saver for "Spin down HD". Uncheck it.

DVD drives don't beep.