2. Click on the application here, which is the function on the sidebar.

3. Then click Utilities at the top.

4. Click on the terminal here.

5. Then, the terminal types the command: sudonvramsystem audioroom =% 00, and then presses enter.

6. Enter the administrator password. There is no display during the input process, so please pay attention. The administrator password is the password set when the computer is turned on for the first time.

7. Then it is not displayed after input, and this $ is displayed to indicate that the setting is successful. There will be no sound when you turn it on next time.