Hi, everyone!
I've heard small earphones that we stick in our ears modify ears inside so that ear doctors give "traumatized" diagnosys. I guess huge headphones are safest from this point of view.
What other actors should be considered? For instance, I'm afraid to repair my old cheap big Philips headphones as they are closed type and might resonate back into the ear. (I read about such feature of $ 15 headphones)