Or there's noisykeyboard.exe, although it really messes with some input stuff... Pidgin crashes as soon as you do any keyboard input with it running.
Also, the Model M speaker isn't driven by the Model M itself, it's driven by the computer it's connected to, an RS/6000 workstation. The RS/6000 moved the speaker into the keyboard, instead of in the case, because the machine could physically be somewhat of a distance from the user.