Thanks for clarifying that. I always thinking it was due to my bad hearing or lack of fluency! English is my second language, and without subtitles, I'm having trouble to understand the dialogues without increasing the volume until I reach a level where I also got disturbed from the sound effects, bg music etc. It's a bigger issue with movies, not only due to what you explained about sound mixing, but also error correction of my brain works worse without the context, unlike series where I know the plot and the characters.