I used to love the DuoPhone TELECOIL option on P2 so it’s one click away if I need it for a phone call suddenly.
From Marvel onwards, that feature was taken away so you can only get phone call in one ear.
This was super annoying as you got the slight interference in the other ear that wasn’t getting the call and also noise that you didn’t want to hear.
The NHS has reduced the gain/MPO to nothing in my left ear so I only get the phone call in my right ear, no background noise or interference in the other ear.
Very clever as it really works. I chose my right as my left always get infections and has done since I was a child. Very rarely my right gets an infection.
Not getting any type of noise in my left, massively helps with concentration on phone calls.