Today we've been on a tour of the BBC studios in "The Mailbox" building in Birmingham, to see behind the scenes of the BBC radio and television.
We were shown round the recording studios of the programme "The Archers", which is the oldest soap opera in the world, since it started in 1951 and has run continuously ever since.
The studio is full of artefacts used for different sound effects on the programme. There are lots of characters and they all live in houses or flats and most of them have doorbells. This board has all the different doorbells on, all carefully labelled so that the right doorbell can be rung at the right time.
It would be terrible if we heard the Grundy's doorbell when someone was wanting to visit Phil and Jill, for example! (English readers will probably understand what I'm saying; others may be completely puzzled!)