You can get a small speaker to connect up to the motherboard although nowadays a solid state buzzer is more usual. Very cheap, just make sure that you connect it the right way round to the F_PANEL connections marked SPKR at the bottom right hand side of the motherboard.
Although basically the same try following this instead of my other instructions as it might be easier to follow.
You can kick in the backup BIOS by shutting down the PSU from the wall, then hold down your case power button in and then turn on the power supply button, a few seconds later the board will start, shut off the power supply then. Then you can turn on the power supply again and power up the board normally and DualBIOS will kick in.