Support hands-free bluetooth mono headsets

[davecraig]

From a user:

I just wish that the program had settings for using a hands-free, for example, in the right or left ear. Because most children use a hands-free.

Obviously this will just be mono, so we need to test it and see how the audio sounds. Then we can figure out what the best approach to audio positioning is for single ear use.

[davecraig]

I just tried my old Plantronics bluetooth headset, here's what I think:

• I can hear all of the audio
• It doesn't sound like there's any positioning going on - for intersection description the audio for left sounds the same as the audio for right.
• My Location etc. don't have any positioning in the audio.

Based on this, I think the main improvement would be to add text to describe direction to My Location etc. If a mono audio output is detected - or perhaps if using the phone speaker - then the descriptions would be extended to include the positional information. Perhaps that could even be done in SpeakCallout by using the information in PositionedAudio?

Or perhaps it is possible to filter the audio in some way e.g. depending on the ear being used, map the stereo left or right channel to the mono headset. If the headset is in the right ear, it may be totally silent for things to the left - or can we boost that a little?