system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are movies so quiet during normal dialogue, yet so loud during music score or action scenes?

Constantly changing the volume is annoying. It seems pretty much all movies made in the last twenty years or so is like this.
gpt
The movie sound recording is mixed for use in theaters, which have different standards for audio levels, having a large dynamic range. Its an artistic choice of sorts, to give impact to loud sounds like explosions, gun shots etc. 

They could of course remaster these levels for home audio, but they don't because it costs money. You can fix this somewhat if you have a surround setup by boosting the center channel volume from your amplifier, where most vocals are panned. Its worse however if you just use the TV or a 2 channel system, because the center channel becomes a virtual channel only (it plays identical sound through both speakers, making it sound as if its centered). While boosting a virtual center channel is technically possible, it requires digital sound processing that would add cost to any playback device.