One thing that sets Macs apart from PCs is the sound they make when they’re turned on. PCs make a rather boring beep noise, which is your computer’s way of telling you that it’s checked its vital components and found them to be okay. Macs, on the other hand, play a noise through the sound card, which is a more pleasant single note.
The problem with this sound is that it can be quite loud, which is especially annoying if you’re using your Mac in an environment such as a library, or where your girlfriend is asleep in another part of the room (which is usually my problem). So, enter StartupSound.prefPane.
As the name suggests, this adds a new pane to System Preferences which controls the volume of the startup sound. You can turn it off completely, or make it quieter.
I personally have the sound made quieter – it’s still important to be able to hear it, to make sure that the computer is okay. But you can mute it altogether if you really want to.
The official version 1.0 is for PowerPC Mac users only, so Intel Mac users will want this version from MacUpdate which is a Universal Binary.