The amplifier on your sound device is going out, and causing the popping noises.
Monitors don't make noises. If it does, it's going to start a fire soon.
It could also be your PSU can't handle your system load.
Your flash ROM is dead that the BIOS is saved to. Recover it with ASUS crashfree BIOS (as listed in your mobo manual). Otherewise, send it back to ASUS for a ROM replacement, or buy a new motherboard.
Only update the BIOS when you HAVE to. Not because there is an update.