How to turn off the annoying speaker beep on Ubuntu

There is a simple and easy way to make sure the speaker of your pc will stop beeping everytime you issue a wrong command.
Try

sudo lsmod | grep pcspkr

If you can see

pcspkr

Turn it off

sudo rmmod pcspkr

Don't forget to make the change permanent

sudo echo "blacklist pcspkr" > /etc/modprobe.d/blacklist-pcspkr

Job done