Interference with Virgin set-top box

I have a Virgin TV set-top box. Worked well for 21 months or so. Then, 3 months ago, sound from another channel began to break in to the programme or app clip that I was viewing. This affected only my hearing aids - my non-deaf wife could hear none of this ! Nor could I if I took the aids out. Very strange. I think I need a new box.
NB - I can’t get through to Virgin on the phone now. The robot asked me for characters from my ‘memorable word’. On previous calls it asked me for bits of my password, which got me through to a real person. There was no memorable word at set-up time 2 years ago ! Has anybody else experienced these problems ? Jim

Ignore the Virgin box cause ! I’ve narrowed it down to my Panasonic TV. I first disconnected the Virgin box and watched TV without it; after a while the interference started up again in the hearing aids. Anybody else had trouble like this with Panasonic TVs ? Jim