When no audio (music, video or call) is running on the two connected devices:
Ear (open) plays audio from the first device receiving the incoming call/making an outgoing call, or from the first device playing back music or video.
When only device A is playing back music or video:
1) Ear (open) switches to device B if there is an incoming call or if device B is making an outgoing call. Calls take priority with Dual Connection. Once the call on device B ends, Ear (open) resumes the music/video playback from device A.
2) When device B starts playing back music or video, Ear (open) plays back audio from the device that first played back music or video.