Some applications in Manjaro linux XFCE edition make strange sounds when you click on them or when you press backspace in text editor.

To disable them use the xset command (user preference utility for X) with '-b' option (controls bell sound volume). For more info see 'man xset'.

in terminal type:

xset -b

Also append the same line into the profile file for your user:

sudo echo 'xset -b' >> ~/.xprofile

Source:
https://forum.manjaro.org/t/how-disable-bios-beep-like-sound-in-some-applications/17094/3