I have a nice pair of noise cancelling bluetooth headphones, and I find it limiting to only be able to connect them to one of my devices at a time.
If you’re working on a Mac, there is an easy way to get audio from both of your devices delivered to your headphones at the same time, without any 3rd party software…
Connect your iOS device and Mac via USB
Choose “New Audio Recording” from the File menu. Now that you have your iOS device connected, you can select it as the audio source. Then slide the audio volume up so the audio from the iOS device is being routed directly out to your default playback device.
Slap on your headphones and enjoy!
All audio from your Mac and iOS device will be mixed in realtime and played out to your headphones.