1. If the headphones establish connections with two devices, and both phones are in an idle state:
a) The headphones will output the sound from the phone that's receiving an incoming call or making an outgoing call.
b) The headphones will output the sound from the phone that starts playing music first.
2. If the headphones establish connections with two devices, and one of the phones is playing back music:
a) The headphones will mute the currently playing music (without pausing it) and then switch to outputting the sound from the device with the incoming or outgoing call. After the call ends, the headphones will switch back to the music-playing connection to resume music playback.
b) No sound channel switching will occur when the device that started playing music later will start music playback.