There are people, Mac fans even, that find the startup sound annoying. As a proud Mac owner, I don’t find the startup sound stressful or annoying in any way, on the contrary, not only that lets everyone know that there’s another Mac user in range but the sound itself indicates that the hardware startup testing has been successful.
Now, for all those who need to know how to disable the startup sound, there are 2 methods, the easy mode or the software mode.
Before you shutdown your Mac, mute the system sound. That’s it! The Mac volume will stay muted as long as you turn it up again.
There’s a nifty software called StartupSound.prefPane (as shown in the screenshot) that will mute/lower the startup sound for you. The good part is that no matter how you alter the startup sound, the system sound remains the same, unaltered. We stronly recommend this method, it’s elegant, the software is getting updated constantly and it’s hassle free.