system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come in dubbed movies they can remove the original voices but let other sounds? Even if it is background noise or music that happens while the actors are talking?
gpt
A movie's soundtrack is made of many different modules. If they recorded with a single microphone everything while it was happening, actors that are far away would be too quiet and there'd be a ton of interference from everything else going on.

So you make one version with no voices, and then each language's team can record and add their own before finalizing it.