I'm not sure that I follow, but do you mean be listening to music on the earphones, take a phone call on the handset speaker, then end the call and go back to t

I'm not sure that I follow, but do you mean be listening to music on the earphones, take a phone call on the handset speaker, then end the call and go back to the earphones? If that's the case then there's literally to switch between earphone/handset speaker/loudspeaker, on my phone at least. Also, isn't the point of a bluetooth handset that you can make the call there?