Switching headsets from watch to phone
How to switch a connected Bluetooth headset from Apple watch to iPhone when answering calls?
iPad 2, iOS 5.0.1, Working with windows 7 and vista
Hi
For assistance with pairing and using Bluetooth headphones in conjunction with more than one device at the same time, I suggest that you consult the manufacturer's instructions or support resources.
Certain Apple and Beats headphones support simultaneous connections and automatic switching between Apple Watch and iPhone.
They include, for example:
AirPods
BeatsX
Beats Studio3