Firefox is finally joining the ranks of web browsers that block autoplaying web sounds. Mozilla's latest Nightly builds for Firefox now include an option to mute autoplaying audio, hopefully saving you from jumping out of your seat when an obnoxious video ad makes its presence felt. It's finer-grained than Chrome's recently removed automatic muting, too. You can turn the feature off entirely, force it to ask for permission and make exceptions for specific sites.