I’m usually aware of my surroundings even with the headphones. Apparently sometimes more than some people without them. I just remove them when I need to interact with others. If I really needs to hear the crap around me, like when I’m cycling, I use bone conduction headphones.

And if it’s so crowded that I need to hear the people around me not to bump in them, then it’s too crowded for me to be there in the first place.