I tested these vs. a set of Bose QC2s and QC3s on several trans-Pacific flights.The result? The Bose went back! The ER6 had more noise reduction and significantly for me much, much better music fidelity than the Bose. While the active noise-reduction of the Bose is excellent I found the isolating characteristics of the ER6s even better. You don't hear anything. Period.While the Bose do have great noise-canceling they are quite poor in sound reproduction. The sound from my iPod was quite muddy and non-defined, The sound using the ER6 was very clear and sharp with solid, well-defined bass, treble and mid-range.As other reviewers have stated it is imperative that you get a good "seal" when you insert them into your ear. When you do these earphones leave the Bose in the dust.