This tweak controls whether the system will beep when an error or invalid entry occurs.
Start a new Terminal session (in Finder click Applications > Utilities > Terminal).
To disable this setting, type (or copy and paste) the following command:
defaults write NSGlobalDomain com.apple.sound.beep.feedback -boolean false
To reset this setting to the default value, type (or copy and paste) the following command:
defaults write NSGlobalDomain com.apple.sound.beep.feedback -boolean true
To activate this tweak please reboot the system.
Close the Terminal session by typing
exit at the prompt.
Disclaimer: Making any changes to your system can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from these modifications can be resolved. Please follow the instructions carefully and use the information provided at your own risk.