It switches back on a whim for the most arbitrary things, though. In Windows the same can happen but I can at least temporarily disable an input if it is doing that.
Doing some things like disabling an input/output device, or an internal keyboard, or a webcam. Almost impossible. Even if there are some ways, they change so often. Let's say you have two cameras and an application that always picks the internal one. I couldn't find a way to disable the internal camera so that this app would pick the only available one.
I "fixed" this with a Hammerspoon snippet that monitors input changes and reverts them:
mic = hs.audiodevice.findInputByName("MacBook Pro Microphone")
function handle_deselected(_, type)
if (type == "gone") then
if not mic:inUse() then
mic:setDefaultInputDevice()
end
end
end
mic:watcherCallback(handle_deselected)
mic:watcherStart()Ah yeah you're right. Does the "Audio MIDI Setup" Mac utility app help you here at all?
It gets close, but no way to truly pin it still. It effectively does the same thing that System Settings > Sound > Output & Input does but with a better UI making it clearer that you are making a change to the primary. But the change is still just as unpinned as it would be from the other location.