It depends how anal you want to be about this, [how much you want to be] about details. A voice that really offended me was the Sontaran in The Invasion of Time, when they turned up on Gallifrey.

In those days we didn’t know what was going to come next in Doctor Who, so as a teenager it was really exciting. So it was really exciting when the Sontarans turned up, and when he finally took [his mask] off he looked great. And then he started talking and he talked like that [puts on stupid, somewhat cockney, Sontaran voice] and I found that really offensive.