Terminal command

VikingOSX wrote:

The stereoAsMono resource does not exist in the Ventura 13.4 com.apple.universalaccess.plist file. Always look at the date of the post when you encounter Terminal commands on the Internet as some may date from a decade or more ago and no longer be relevant in the current operating system.

This option still exists in System Settings->Accessibility->Audio:

I set it in the GUI, and then I tried

defaults read com.apple.universalaccess stereoAsMono 

and the output was 1 (indicating that it was set).

I turned it off and the same command now produces 0.

So the command

defaults write com.apple.universalaccess stereoAsMono -bool true

seems to me to be the Terminal equivalent of setting the toggle shown in the image above.

The stereoAsMono resource does not exist in the Ventura 13.4 com.apple.universalaccess.plist file. Always look at the date of the post when you encounter Terminal commands on the Internet as some may date from a decade or more ago and no longer be relevant in the current operating system.

It writes a preference setting to the UniversalAccess preference list file.

It wouldn't exist in my .plist until I made that selection you have shown and I almost never visit Accessibility… 😎