How do you ask your colleagues to be more... sensory friendly

1. I am working on a musical project as a director

2. Directors stay in the same room with the singers as we discuss things (we dont really have another room)

3. The singers talking to each other and practicing singing overlaps our discussions and are a total sensory nightmare, and i am having a meltdown almost every day after i get back home

4. I do ask them to be quiet when they're just chatting but they listen to me for like 5 seconds, and i feel like i have no right to stop them when they're just having their free time

5. Tried headphone, is not enough

6. I don't want to have a serious conversation with them about my autism

What would you do if you were in my situation?