It is unlikely to be a Sonos issue. They’re most likely playing what is being passed to them via the ARC connection. You may want to check on both the TV and Virgin Media to see if they have software updates which may alter this problem. 

Hi,

Thanks for replying. I’ve checked and everything is up to date. I’ve posted on the VirginMedia forums too. They did have an update about a month ago - didn’t mention any audio changes - but mine’s only been like this the last few days so it’s just a bit baffling to me. After some more in depth testing the bleep happens when going Stereo PCM to Dolby channel/show not vice versa though if that helps give more info. Thanks

Are you using their TiVo box and older service or their new TV 360 service? I’m a VM user but I’m using the old TiVo box and thats working fine here… no issues seen when switching between the different codecs or channels.

Hi,

Yea it’s the 360 box. Had it over a year with no issues only just within this last week suddenly a problem. Thanks

The one thing perhaps worth trying is re-seating, or trying a different HDMI cable from the Virgin 360 Box. I am assuming that the TV freeview tuner (if used) and all other connected peripherals are working okay?

As Bruce mentions, it’s likely the Sonos device is just playing the audio it’s receiving from the TV - try the HDMI-ARC/eARC port on ‘pass-through’ (if supported) and see what happens if you switch between ARC & eARC on the TV too, if you also have the option to do that.