Muffling iMac start-up chime

[Jack W]

How do I muffle the iMac startup chime???
It's back on since I reset the pram.

Thanks, Jack

[Xairbusdriver]

In Terminal, type (or copy and paste) the red text below. You may be asked to type your Admin/computer password. You will not see anything while typing your password (in Terminal). Just type it and press return.

sudo nvram SystemAudioVolumev=%00

[Jack W]

Xabd,

That worked after I removed the extraneous v before the   =    sign:

sudo nvram SystemAudioVolumev=%00  to:
sudo nvram SystemAudioVolume=%00

Now, the cat won't jump out of her skin every time I boot up the iMac

Just kidding, I don't have a cat.

Thanks

[Xairbusdriver]

Sorry, didn't see and don't know where that "v" came from. Possibly from our deceased cat?!

The free Cocktail.app can also turn that sound OFF/ON.

[jchuzi]

Cocktail is only free for a few trials. After that, you have to pay the piper.

Actually, I don't think that it is a good idea to completely disable the startup chime (which Cocktail can do). Muting is fine, and can be done via System Preferences > Sound > Sound Effects. If you disable the startup chime, you will find it difficult to do anything that requires modifying the startup sequence (for example, booting into Recovery Mode) because you have to press the required keys (in this example, Command-R) immediately after the chime.

[Xairbusdriver]

Cocktail is only free for a few trials. After that, you have to pay the piper.

My bad, it does cost 20 bucks. But I don't think I've had to pay for any updates. And it is nicely maintained for every new OS. It's basically a GUI face to what can be done in System Prefs and/or Terminal, but it eliminates the possibility of typeing ererz en the infuorgiving Terminul invironmint!

BTW, I've been disabling that sound for longer than I can remember (even before OS X). Nor can I remember any problems with special startup procedures. Your milage may vary. Even wrote an AppleScript back in the days that muted sounds at Shutdown. Another one ran at Startup to UN-mute sound.

BTW #2: I'm pretty sure that the "Muting" available in System Prefs mutes all sounds, not just the Startup sound/chime.

Some newer Mac's apparently have the Startup sound muted by default (OSX Daily)! So, it may be confusing for those users to wait for a sound that Apple has deemed less than critical. If you have a newer Mac that operates like that and want to hear that sound, here is another Terminal command that should help:

sudo nvram StartupMute=%00
You will note that this uses the StartupMute
setting instead of the SystemAudioVolume.
Just the other side of the coin.

Of course, Cocktail already 'knows' which OS we are using, so all we have to do is remember to use it. It's your computer, despite what Apple says about repairing it. Use it responsibly; don't scare cats or sleeping spouses!