Most theaters, at least in the U.S., have assisted listening devices available. You can usually pick them up from a little booth in the lobby, leave a driver’s license for security, wear them during the show, and return them at the end. You’ll need to take off your hearing aids, so bringing a case for them is a good idea.
I’ve had good ones and bad ones. The technology is improving, but there’s a lot of quality variation.
There’s no drawback to trying them - if you don’t like how they sound, you can just take them off and switch back to your aids. I always tell the person staffing the little booth if they’re bad, in hopes that they’ll get better someday.
Hearing aids are pretty terrible for live musicals. The assisted devices can be better, if they’re good ones and if the sound is mixed with them in mind.