Heart Monitor Type Beeping Sound


I'm using a PowerBook G4 Titanium with a 1 GHz processor and 1G of RAM with 10.4.2 installed.

When it's very quiet in my office and there are absolutely NO programs open on the machine (except for dashboard and finder), I can hear a heart monitor type sound coming from what I think is the top left side of the computer. It goes: beep........beep.......beep.......beep......etc. and it's very very faint. Muting the speakers has no effect. It sounds like a beep made when my battery is low on my phone. Any ideas?

The question is as I originally fomulated it. However, later information was left off the post. I had said that I had isolated the sound that I heard originating when I plugged in my USB HP psc2410 printer.

So unplugging the printer from the USB port makes the sound go away?

If the magnetic shielding on the speaker is damaged, then signals running to the nearby USB port might interfere with that speaker. I'd get an Apple tech to have a look at it.