Very disappointed with these headphones. After 1 week of using with my ipod, the right side stopped working. I returned to Amazon and they graciously gave me another product (expedited). The noise canceling was not very good but I lived with it. Now after a few more months, it is again not working properly...for songs, you can no longer hear lead vocals, just the instrumentation and background vocals. For audio books, there is no sound at all. It's weird and I'm baffled. Don't think it's user error, as there are no settings on the headsets. Even cheapy headphones that I've had for years still work. I used these for running so maybe they were not meant for that?!