Is it? [He glances around] Oh, right. Yes. Of course it is. Must have taken a wrong turning somewhere.
No? [He squints, leaning in to examine the cavern of one of Sam's ears. Is there such a thing as personal space? Perhaps, but he's never quite met it] What would you call it, then? It's not four beats, is it? [The Doctor is staring back at Sam's face. This answer apparently holds a good deal of weight to it]