When I listen to the music using the headset and I have income call, the music in the headset mutes and phone rings via the speaker, there is no income signal in the headsets.
When I receive PIN messages I can hear that signal in the headsets.
I have two q10, both have the same problem.
Most likely a bug that BlackBerry will need to fix.
This has always been this way and I never understood why.
It depends on the headset and the bluetooth stack it uses. Mine stop the music and say the name of the person calling (Parrot Zik2.0).
I'm pretty sure the OP is talking about wired headsets !