Many Mac users will remember that your Mac used to “ring” when you started it. Apple removed the chime in 2016, but with macOS 10.15 Catalina, users were able to reintroduce the chime through a command in the terminal.
The chime is back by default in macOS 11 Big Sur. In the short video below you can hear how the carillon sounds on my (beat-up) 2014 MacBook Pro running Big Sur beta.
If you mute your Mac before turning off, the chime will not play the next time you start your computer. To turn off the chime, Apple has a setting in the sound system setting that you can adjust.
You can also turn off the chime in the terminal. Here are the steps.
Launch the Terminal app. It’s in applications > Tool.
Enter the following at the command prompt:
sudo nvram StartupMute=%01and then press Return.
You may be asked for your user password. Enter it and then press Return.
You are finished.
If you want to switch on the clock later, use the same instructions above in the terminal, but in the second step of the guide type
sudo nvram StartupMute=%00 instead.
Editor’s note: Updated 1/10/20 with the sound system settings setting. (Hat tips for @BlueJayPilot.)