if the "beep beep" you're wanting to disable is when the computer POSTs you may need to open the case and simply disconnect the speaker cable.
still, you may be able to disable the speaker from beeping while linux is running but that setting wouldn't likely have any effect on the POST beeps because linux isn't running at that point so you're still going to hear those.
otherwise, i'm interested to know if it can be disabled while linux is running as that could still have some value... at least "less" beeps.