That’s a nice feature. I wish there were headphones that did that well. (My BOSE, even with sound-cancelling off, block a lot of the ambient sounds.) I had a lot of ear infections as a child, and was made to wear earplugs to swim when I had minor infections. And as a result, I really really hate the feel of stuff in my ears. I tried earbuds once, and decided that’s not for me. I am frustrated that all of the high-end sound equipment tends to be developed in that form factor.
I’ve had decent luck with one-ear models, and they leave the other ear open to ambient noises. Mostly, when I wear headphones, the point is to spare others my background noises, or to spare the people near me the sounds of my co-workers. Not to block myself off from where I am.