You could try Panasonic - I did and they didn't care. But then neither did VM or Sky - they said it was the others party's problem. It has been going on for a few years now.
I don't have the isse any more as I plug the devices into an amp direct and by-pass the tv.
Do a search for 'Panasonic', 'Dolby Digital' 'high pitch', 'beep' etc in the VM and Sky forums to see it a known issue.
But just to confirm that although 'Panasonic' is the main tv manufacturer with the issue - it does occur on some other makes.
Seen reports of Samsung tv too - but the common issue where the fault is heard seems to be using ARC.
Beep when selecting HD Channels
Sonos beam beeps for dolby digital
Sky: High pitched sound when changing between Sky HD channels
1.2Gb/55Mb in Oxford (area 31) using SH5