Do you mean the dialogue audio is very low so you can't hear it over the other sounds? Need some better details, what equipment do you have, is this happening with every source and every video, did it always do this? You may want to try some external speakers, some soundbars actually have a dialogue booster since this issue with low speech is pretty common
https

/www.howtogeek.com/218949/htg-explains-why-the-dialogue-on-your-hdtv-is-too-quiet/
https

/www.cnet.com/forums/discussions/how-to-fix-very-low-dialogue-but-very-loud-sound-effects-1/