How do I turn off startup sound?

Thank you, worked like a charm, no more waking the neighbours when I start my computer

Do I have to press them both at the same time or the mute button first or the power button first? I really don't get it. That's what I'm trying to do every time I turn on my MacBook and nothing happens. Still the same.

Amazing... that after all these years buying and using Mac's - that I am STILL annoyed by the loud start-up chime and having to take my TIME to search for a solution. Proof again, that some of the smartest people in the world (Apple employees), can also be some of the stupidest. PLEASE take a few minutes Apple and fix this irritating sound.

I only mind the chime when I need to start to silently. I'm not so tech savvy so all the script writing is not for me and I've tried holding down the mute button and putting in headphones with no luck.

What I did this morning was to turn on my computer and then I immediately put down the screen it before it had a chance to chime and then opened it again 3 seconds later. It worked and my son is still sleeping 🙂. While its not the ideal solution, for the few times I need to start up silently this should work.

Hi!

It worked for me, but I had to change the quotes to the plain single quote.

I HAVE JUST DISCOVERED THE SECRET: Press the round start button, wait to hear a two part sound from inside the computer, sort of a wawa woo. Listen for it . it is a low sound ! Immediately press and hold down the speaker icon mute button. for a second or two. Then release it. The screen will appear with no sound. It takes a few tries to get it right , but it works for me. Then try and duplicate the procedure once you get it right. Good luck.

It's 2016, owning a MacBook Pro Retina mid-2015 with macOS Sierra, and there is STILL no option in Settings to silence that sound, and ONLY THAT sound.

If you silence your system sounds before you turn off your computer, yes, you won't hear the startup sound when you start your computer.

BUT, this creates two problems:
1. you have to actually remember to do that before turning off your computer. And it's annoying as **** to press shut down and remember mid-way that you forgot to press the mute button. Will you start back your computer just to put it on Silent? NO! Nobody in the right mind will do that.

2. you have to remember to turn it ON again after you start your computer up again, otherwise there is no sound for you in the OS.

I mean, seriously?

How about an option in Sounds -> Chime - OFF? To silence ONLY the chime and nothing else.

Would that be so hard to implement?

Thanks! For me worked SystemAudioVolume=%00 from second reboot. iMac, OS X Sierra.

Does this mute only the startup sound or all sounfs?

All sounds.

The writing a script method with terminal works, at least in so far as muting the sound on startup.

Worked fine in Mac OSX Sierra, thanks.

Kuhak's answer worked on my new 2016 macbook pro! yeah!!!! This is one of the first things that I do when I get a new computer and this was an easy fix.

Works great in sierra 10.12.2

😀😀😀

Thanks!!

sudo nvram SystemAudioVolume=%01

El Capitan 10.11.6

Download auto-mute software, and put it in the dock. Select the "open at startup" option. No chime.

If you want the chime back, just remove it from the dock, or deselect the open option.