Yup! You nailed it. the primary concern of movie producers and the sound effects guys is to make sure you do not think the doorbell is ringing as you sit in a movie theater and watch the film… Even more so so you do not get up from the couch at home only to find that no one is at the door!!!
Boy, it boils my blood when I hear a text alert that sounds JUST LIKE the one on MY PHONE, and I look at my phone and discover it wasn’t MY phone, it was someone else’s IN THE MOVIE!!! It’s so ANNOYING!! Why do they DO THAT??
Indeed, fairly distinctive mannerisms between him and his various sock puppets.
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Back to the OP, depends on the era? If buzzers were common in the setting of the movie, it would only make sense to use a buzzer.
Can’t say that I’ve ever noticed a door buzzer in a movie that seemed out of place.
I just know that in a recent Beavis & Butthead episode that I watched, the doorbell to their house buzzed. I guess it makes sense that they do such. Someone, especially if they’re in a different room when the TV is on, might mistake a “ding dong” for their own doorbell.