Simple and effective solution to mute the boot sound of Mac computers.
The only effective way of disabling the boot sound, without resorting to hacks, is to mute the Mac before shutting it off. This script works by muting the Mac right before shutdown and by restoring the volume state after the login.
With nobootsound, you won't need to remember to mute your Mac, and you will get rid of the boot sound, which can be very annoying, especially if you have to boot in places where silence is golden, such as libraries, classrooms, conference halls...
To install the script, run the script install.sh with administrative privileges:
sudo sh install.sh
This script will just copy two files in the /Library/LogHook folder and register them as hooks for login and logout, so that they will be called each time the Mac is shut down and powered up.
To uninstall the script, run the script install.sh with the -u flag with administrative privileges:
sudo sh install.sh -u
The script doesn't work when headphones or external speakers are plugged in. This is due to the fact that the chime always comes from the internal speaker, but this is not accessible to Applescript when the headphones are plugged in.