How does the Apple Mac system completely shut down the boot sound?

Mac users are aware that each time the power on, there will be a "duang~" start-up sound, sometimes the sound is larger, but also startled. If you want to temporarily prohibit the start-up tone, there is a simple way is to always hold down the keyboard on the Mute key (F10), but this method is not a cure for the symptoms.

The following PC6 small series to introduce a thorough solution:

1. Open "Application", open "utility", find and open the [terminal] program, then enter the following command and return (note, do not copy more space when copying):

sudo nvram systemaudiovolume=%80

2, after you will be prompted to enter a password, enter your user password, carriage return, as shown below. This will then be completely muted when you start the Mac again.

(Note: Enter the password is not visible, not like the normal input password can see, you just lose it, enter the end to press ENTER.) )

3, if you want to return to normal power-on blunt, as long as in the terminal again enter the following command:

sudo nvram-d systemaudiovolume