I checked our Cabin Safety Manual, and here we go:
Portable Electronic Devices Permitted for Use at Any Time
• Noise cancelling headsets. (Must not be connected to PED during
taxi-out, takeoff and landing.)
Then, a few bullet points down..
• Passengers’ own head-set that is not plugged into a power source or is
turned OFF if battery powered.
I think this could be clearer!