There is still something intimate about having voices in your ears, I think, and allowing your imagination to fill in the pictures,” says David Tennant. “There’s something quite potent about that. We’re very fortunate in this country in that we have Radio 4, which is a wonderful resource for such things, and it uses a slightly different part of your brain. Obviously, it taps into your imagination. But it can be very seductive, audio drama. I love it. I listen to it a lot, and it takes you somewhere. It fires up a particularly emotive and exciting part of your brain.”