Lowering volume below minimum setting

Hello, Is there a way to make the iPhone and/or iPad get quieter than the lowest setting without muting it? Often, when I have a headache, the lowest setting is still too loud to listen to music on headphones.

I just got off the phone with the accessibility team, and no one there had a solution. I put in a feature request, but that doesn’t help me right now. I would really appreciate any help anyone could offer. Could a third-party equalizer app be an option for making the music quieter?

Thank you.