Off at a tangent here, but I once had a girlfriend who had a cochlear implant (effectively bionic hearing). A magnet and electrodes are implanted within the head - the purpose of the electrodes are to stimulate the cochlear thus allowing the deaf to hear (supposing the auditory nerve is OK), and the magnet is there to hold a transmitter firmly in situ outside the skull.
The advice given by the cochlear implant centres is that this device should be turned off for TO and landing however when asked, neither Boeing or Airbus provided a conclusive answer. To me this seemed to be a problem as here was a SLF who needed to be transmitting in order to hear the safety briefing.
So
Not quite the same, but we did about 2.5 hours of testing with her in a Cherokee - try as we might, it was impossible to get her to interefere (well, interefere with the avionics - she was a natural pilot when interefering with the controls, and incidentally the deaf who have hearing corrected with a cochlear implant are NOT precluded from a class 2 medical).
The next step was on an A320. I was also SLF on this occasion, and pre departure talked through my tests with the P1. The result was that he was happy to contine our test on this flight. We put her "down the back", as far away from the e-bay as possible. All was fine.
Its just a thought should anyone encounter a cochlear implant PAX in the future.
And one other point - I have no idea what frequency range these contraptions work within, but the various cochlear implant centres are always willing to field intelligent questions.