Turn off startup chime

Question

how can I turn off the startup chime, which I hate and makes it impossile to turn on the machine silently eg in bed!
<Edited By Host>

Answer 1

Paste the following script into Applescript, compile it,then save it as an app called silent shutdown. Move it to your Utilities folder. Then drag it to the left side of your Dock, creating an alias there. Launch the app from the dock to always shutdown your system. While shutting down, it will set your volume to zero, ensuring the next startup will be silent.
tell application "Finder"
    display dialog "What would you like to do?" buttons {"Shutdown", "Restart", "Cancel"} default button "Shutdown" with icon caution
    if button returned of result is "Shutdown" then
        set volume 0
        shut down
    else if button returned of result is "Restart" then
        set volume 0
        restart
    end if
end tell