It used to be that you could edit /etc/modprobe.d/blacklist and add “blacklist pcspkr” to turn off the console beeps entirely on Ubuntu / Kubuntu.  As of 9.04, the module is now called “snd_pcsp”.

So, to turn off console (not X terminal, but tty) beeps, you can do one of the following:
1) (This is my preference)

echo blacklist snd_pcsp >> /etc/modprobe.d/blacklist.conf

2) (I’ve done this, but it doesn’t affect all software)

for i in 1 2 3 4 5 6
setterm -blength 0 > /dev/tty$i

3) (Only works per shell if ~/.inputrc is included)

echo set bell-style visible >> ~/.inputrc

Enjoy more-sane editing from ttyX in the future!