Hi, Thanks for replying, incidentally, its Paul in Leeds, not Pauline! (and I don't live in Leeds any more either but that's by the by!).
Going to have to start taking notes of when and where the problem occurs to start pinning it down but to start with after we'd watched Dragons Den on BBC2 HD with loads of drop outs we switched to ID and experienced none whatsoever for the next hour. Definitely seems to affect some channels only. Have got Netflix and Amazon Prime so will start logging any issues when watching them and report back.
System wise we've got a 2 year old Sony OLED tv, 2 year old sonos sound bar and the V6 box which is coming up to 3 years old. The sound drop outs aren't new, have been experiencing them for as long as I can remember but not all of the time so does point to a specific issue rather than something more general.