I would also be anxious if I couldn’t do any any deep thinking in silence. It is unbelievable how bad co-work spaces are for for thinking.

Personally I use my trusty Bose over ear noise cancelling headphones when i’m with a customer that has loud open plan offices. I’ve had my Bose headphones for almost a decade now. Today I use them even when I’m at my office which is quiet But because its open plan I still get distracted and we are working on acoustics however most of us are deep thinking engineers and we have a liberal work from home policy so our work environment is good enough to get stuff done.

I would talk to someone you have value to the startup and people don’t even think about this till its too late.