Audio problem: In the uncensored version (certain scenes were thought too graphic, and thus a lot of copies of the movie are edited), Dracula picks Renfield up and strangles him, and Renfield is screaming. Okay, how can someone scream if they're being strangled? (The censored version, however, works because you can't hear Renfield).
Dracula (1931)
1 audio problem
Directed by: Tod Browning
Starring: Bela Lugosi, David Manners, Dwight Frye, Helen Chandler
Visible crew/equipment: Right after Dracula says "My blood now flows through her veins", he then walks across the room. As he does this, watch the lower right corner of the frame and you'll see revealed for a moment a big glaring light "hidden" on the floor behind the couch. (00:58:45)
More quotes from Dracula
Trivia: To accommodate all sorts of viewers, the studio also made a silent version of the film (for cinemas without sound equipment) and a Spanish-speaking version (to be shown in Latin America). The Spanish version is considered a better film, because it was filmed after the English takes each day, so the Spanish director and actors would watch the English takes and decide how to improve on them.
Answer: So he could seduce Mina slowly with his hypnotic eyes, Dr. Steward would have been in the way.