Audio capability discovery

Hello all, I'm unsure this is the appropriate method of contact as I'm just
a lowly frontend developer but I hope my idea resonates with some of you to
get a discussion going.

I feel developers should be able to know if the computer is currently
muting audio or has no working audio outputs. This allows us to
programatically deal with the following types of situations:

   - Users has auditory disabilities
   - Users with disabled / no audio hardware
   - User has muted audio output

Potential use cases:

   - User is deaf and automatically receives closed captions without
   interaction
   - Pausing media if user mutes audio outside of the application
   - Notifying user that there is required audio content as part of a
   presentation if no audio hardware is available

What do you think?

- Lorin