The startup sound on my 2016 12" MacBook is so annoying. I need this to end and hope that I'll find help here. I am not able to mute it with the Terminal and these commands that you can find online: sudo nvram SystemAudioVolume=%80 sudo nvram SystemAudioVolume=%01 sudo nvram SystemAudioVolume=%00 I had an iMac before I went for the MacBook and the commands didn't work with this machine, too. But I was able to use the small program "Auto Mute" ( https://www.macupdate.com/app/mac/35207/auto-mute ) but it seems as if this doesn't work with Sierra anymore. I also downloaded a script that should mute the startup sound, which worked fine for a few weeks but now that I am using Bluetooth Speakers instead of the built-in speakers the startup sound is back again to annoy the crap out of me. Any suggestions?