Who knew? It seems that these audiobook-exclusive stories done by the Beeb are well popular in the UK. Sometimes they get other cast members to narrate, like Freema Agyeman, but in a recent one called Doctor Who: Pest Control, the reader is Doctor number 10 himself, David Tennant.
The really amazing thing is, if you like language as much as I do, that Tennant does all the characters (after the fashion of these British audiobooks) and each one is in a different British accent. The narration is in his voice, which is Scottish. And of course, he does the Doctor himself in his semi-posh accent. And he does a cracking job imitating Donna Noble. Throw in some Irishmen and a Northern accent or two and you've got an encyclopedia of speech patterns.
It'll be hard to find this recording at your local Barnes & Noble, but you can download it from iTunes.