The specs for these headphones, in the "Connectivity" section say that it can connect 2 devices simultaneously. My hope is to have these for my father and my father-in-law, who are both hard of hearing, but have their cell phones ring thru into their ear, and then be able to take a call. I believe Sony's WH-1000-XM4 will do this as I spoke to the Sony presales support. Sennheiser support said this model would also swap between bluetooth connections for my objective.
The issue for me, and the only way I can determine this, is to test them so I'm buying both to test. The user interface is critical, because if you must navigate thru menus on a small smartphone....that process would likely be too frustrating for very-seniors (95 and 101!). We will see!