When the announcer announced the actors' names at the beginning?

Did you have Audio Description activated on your set top box?

Ah, that might be it. Thank you!

You were right. I'd accidentally activated it! I'd never heard it before. It made me laugh!

AD once randomly appeared on my tellybox during the episode of The Tudors where Francis Dereham was hung, drawn and quartered.

I can confirm that it is indeed descriptive

Might one day watch something with it on for a laugh.