On Tuesday evening, the family was out until 9 o'clock, I was listening to music fairly loud and had Obsessive Compulsive Cleaners (a TV programme) on silent.
A new character was introduced, and as soon as he started talking, I got the impression that he had a northern accent (i.e. Yorkshire/Lancashire) - even though the sound was off. It puzzled me, so I continued watching to see if I could guess the others.
Good old Hayley speaks pure Estuary/Essex, I would say that was obvious from the way her lips were moving but I knew the answer, so that doesn't count.
One cleaner clearly looked a bit foreign anyway, but when he spoke, it was also obvious that he had a foreign accent; one guy appeared to have a Welsh accent and the last lady to be introduced appeared to have a Brummie accent.
Having thus made my guesses, I turned up the sound again for the last bit to see where they came from and, basically, I got them all right. The even weirder thing was lady who I thought was a Brummie didn't have a strong regional accent at all, but she came from Derby (which is not that far from Birmingham).
