"The ER-4Ps are excellent at reproducing accurate sound from a recording. If you are listening to sub-par source material, you'll know it. With a great recording, you'll be inundated with all of the sounds that the producers wanted you to hear. I didn't find any part of the audio range that was lacking. It was a treat to experience my music collection with that full-range, emphatically detailed sound that comes from this set of headphones. And you don't hear anything else, thanks to the superb isolation that Etymotic has accomplished with the ER-4Ps."