If you are planning on watching "Birdsong", part 1 being broadcast on Sunday evening, you may be interested to know that some of the sound effects in the sappers' tunnels scenes were recorded in the Godstone quarries to get a real underground confined space effect. It was a fascinating day. We recorded footsteps at walking and running pace, bodies being dragged around, spoil being shovelled, water trickling, heavy breathing (don't ask!) and lots of other incidental noises.