Muting does not work on my iMac running Leopard. I think this is a feature of Leopard. You can only stop the sound if you use one of the software solutions above (or write your own in Terminal. No idea how to do that here). 10.4 or earlier...no problem, just mute or reduce the volume before last shutdown.
I would like to hear the chime...at about 5% of its current volume, precisely because of the "POST", however, I've suppressed mine, so I can stop waking up the rest of the house when I power on in the morning.
I liked the goat idea, however a pillow cushion is more available in my neck of the woods. The sound is annoying to me also for various reasons.
On some older models if you just close the lid down to about a half inch open after starting the bong will not sound, however, that does not seem to work on my new Macbook, so you might try that depending which model or OS you have (not sure which facilitates the function, model or OS).
Thanks to the poster who linked to the app that turns off the bong, however, I refuse to pay $15. and load yet another app just for one tiny function that is an obvious system flaw. The sound is there as a marketing tool to let everyone in the vicinity know someone is using a Mac, so don't expect it to be optioned anytime soon. In fact, I assume it is copyrighted. As a diagnostic verification it is to my knowledge unnessary because in the case of a system problem the computer will give you one of many various dialog box notifications anyway.
The preference pane:
http://www5e.biglobe.ne.jp/~arcana/S.../index.en.html as mentioned is free and easy to use, and it does mute the sound, however, the volume slider has no effect on my macbook 17 OS 10.5.6.
You could simply turn the computer on just before going into class and then close it up and open it again in the classroom. Or, you could use the outdated method of arriving to class on time, but that would probably change your whole lifestyle, nah forget that one.
