Recognize change in audio input source

[matthme]

If the audio input source changes, Presence should automatically detect this and adapt accordingly or at least offer the option to select from all available audio sources.

[stephenpurkiss]

Problem/Motivation

When I disconnect my bluetooth headphones Presence doesn't recognise the change in audio input source, however, when I connect my headphones Presence does.

Steps to reproduce

I'm using a Mac, so that may be a factor.