Help me help my brother's dog [not spam]

Hello all, Recently, my brother's dog has been trained to react to the smoke alarm - all well and good since my brother is deaf. Unfortunately, the double beep which the USB hotplugging gives when he boots (recognising mouse) and plugs in his camera also sets the dog off! So, question is, how might I go about getting rid of the beeps? I've unplugged the on-board 'speaker', but that's not really a permanent fix... Still, if it means resorting to the source I'll leave it at that! Cheers Dylan -- It is a dark day...