The LA Theatre works production contains a low, resonant note, similar to tones one might hear during a tense part of a horror movie. The Doctor then begins to speak.
The dialogue in the LA Theatre Works production is much more natural than the Librivox dialogue.
Stage directions are included in the Librivox production.
The LA Theatre Works production contains sound effects.
The main difference between the two productions is that the LA Theatre Works audio is more immersive and feels more theatrical. The characters in this version display more emotion in their voice and are more believable overall; it seems like this version has higher production value than the Librivox production.