They do offer some sound isolation, however if you want better results, I suggest swapping the stock cushions as they have VERY thin rubber. While the headphones will stay put with vigorous activity, I found that the seal would un-seat due to the thinness of the cushions. I replaced them with a set of cushions with thicker rubber. They now have excellent sound isolation and are rock solid. I no longer lose seal. Pick up some generic cushions here on Amazon or try swapping cushions off of another set of earbuds for the best function. They work GREAT now...I love these things!