ADR

Automated Dialogue Replacement (ADR) is the formal name for a specialized kind of dubbing. It is used by filmmakers to record dialogue after principal photography has been completed. However, it is a more precise term than "dubbing", as dubbing also refers to the process of having different actors record the dialogue of the original actors in another language. ADR is thus a process used to achieve the final audio track of the original version of a work. Other synonyms include Additional Dialogue Replacement, looping and, chiefly in the UK, post-synchronisation.

The general reason for needing to perform ADR is because of heavy background noise that was captured while a scene was recorded. Alternative reasons include a need for better stereophonic separation or just better enunciation on the part of the actor. Occasionally, however, entirely new lines (such as narration or a correction to a scripted line) might be required to be recorded.

All post-JNT versions of televised Doctor Who have made extensive use of ADR, as it has become standard filmmaking practice to re-record most dialogue. Additionally, lines which are treated with vocal effects are now often dubbed back into the audio mix after a special ADR session. However, this technique was hardly used at all during the monochromatic era of Doctor Who, and generally was too expensive for even color Doctor Who budgets to bear. Even "treated" voices, like those of the Daleks, were often captured live by the same microphones covering the main actors. Nevertheless, ADR was sparingly used, largely when there was no other choice.

A good measure of the importance of this craft can be gleaned from the credits. In the original series, the closest credit to ADR is that of "Special Sounds" — mainly describing foley work — attributed to Brian Hodgson from An Unearthly Child to The Sea Devils; and to Dick Mills from The Mutants to Survival. However, as of the original broadcast of "Forest of the Dead", Tim Ricketts has been the credited "Dubbing Mixer" in every episode since "Rose".

An ADR recording session was featured on CON: "Look Who's Talking". In this episode, David Tennant gave an opinion about ADR shared by many actors:
 * "I don't enjoy recording ADR — which is no secret to the people who have to record it with me. I find it difficult and frustrating because you're not there.  You're not in that moment anymore.  You're not looking that actor in the eye.  You're not experiencing that story in the way you experienced it on the day that you shot it."