Sometimes, when no sound card and/or speakers are available, it can be handy to use PC internal speaker for notifications. Command-line interface to this feature can be installed with Pacman.
# pacman -S beep
By default, beep command can be run only root, but other users can be allowed to run it also, by changing permissions of the beep command.
# chmod u+s /usr/bin/beep
While many people are maybe happy with the traditional beep sound, some may like to change its properties a bit. The following example plays slighly higher and shorter sound and repeats it two times.
# beep -f 5000 -l 50 -r 2