Startup Chime Persists After Downgrade From Big Sur

[SpaceGrayAlways]

Earlier this week I had upgraded to Big Sur on my Mac mini, and a few days later (after realizing that Steam was completely broken) decided to revert back to my Catalina backup. After a restart, I was surprised to see that the startup chime that returned in macOS Big Sur persisted. Every restart had that good 'ol chime again.

I am posting this not because this is an issue, but because I am curious if this means that other users can in fact activate the chime on macOS Catalina.

To be clear the steps I took over the last few days were as follows:

1. Time Machine Backup Completed
2. Installed macOS Big Sur
3. No further Time Machine Backups saved
4. Launched Recovery Mode
5. Using Disk Utility in Recovery Mode, Erased the Mac mini
6. Through Recovery Mode, reinstalled macOS Catalina
7. Imported all content, settings, and apps from the Time Machine Backup in step 3
8. Restarted computer to find that the Chime still existed

 

[MacHiavelli]

Onyx > Parameters > Login > Startup Sound On / Off

OR

Terminal:
ON=
sudo nvram StartupMute=%00

OFF=
sudo nvram StartupMute=%01

 

[dryjoy]

I activated the chime on my 2018 Mini a few months ago via the terminal, was very relieved to have it back. Glad it’s returned in Big Sur.

 

[SpaceGrayAlways]

I wasn't aware that this was available through Terminal, but interesting that the Big Sur install does this automatically.