Headphone connected signal

Dear group,

It would be useful for potential media player applications that use the Web Audio API, to be able to know when headphones are connected, especially on mobile platforms. It seems somewhat related to the discussion of the Audio Output Devices API, but I would appreciate some thoughts/advice from the more experienced amongst you. Is it feasible to create an API call that would tell you if headphones are connected (provided that the underlying system can know obviously) and if so where should this request be directed?

Thanks,
Chris Pike
Audio Team - BBC R&D