

If they’re not prepared to turn down the TV to a reasonable level that’s on them. They know it’s upsetting you and are prepared to continue upsetting you. That’s really unhealthy and inconsiderate behaviour.
One thing that might help is getting them to use headphones with the TV. Most TVs these days have Bluetooth support. If I’m watching a movie late at night (common) I’ll always use headphones. Again it’s just common courtesy.
FTFY
It could work if done selectively on key areas that are statistically slanted to one side, but the logistics of pulling that off and keeping it a secret mean it’s just not a logical conspiracy.