Psst 2.1.1

Tweak or completely mute the volume of your Mac's startup sound. Manage the volume configurations before you shut down your Mac and after logging in. Check the compatibility with your Mac model since the application works only with a limited number of them.

Psst is a faceless application that lets you adjust/mute the volume of your Mac's startup chime. Double-Click "Psst!" in the Finder to adjust the volume settings. Important: The method Psst! uses to change the volume does not work on every model! What it actually does: It simply adjusts the volume settings before shutting down and after logging in.