Disable the Startup Sound

os-x-10-10-finderTo permanently mute the startup sound, open the terminal and type:

  • sudo nvram SystemAudioVolume=%80
  • sudo nvram SystemAudioVolume=%01
  • sudo nvram SystemAudioVolume=%00
  • sudo nvram SystemAudioVolume=” “

Its depending on some models.

To restore the startup chime, type:

  • sudo nvram -d SystemAudioVolume

To temporarily disable the startup sound, just press the “Mute” button on your keyboard (that’s the F10 key on a MacBook) before shutting down or restarting your Mac.