I recently purchase this model after compare to the Koss unit . what clinch the purchase for I be actually go to Panasonic 's site and check out the specification . this be the headphone they sell with they portable dvd unit . I buy this set of headphone to go with my new laptop , which also have a dvd player , and I think they would be useful for that task .  the effect of the noise cancellation be very nice and something that isnt very easy to describe . the best term I can come up for it be `` active silence . '' you can `` hear '' something in that the `` something '' you hear be different than the ambient noise , but its just dead quiet . very useful when youre work around computer .  the sound quality and the construction of the unit be my two beef .  First , the headphone do hiss a bit . there be a audible background hiss just have they plug in . this do go away pretty well when the noise canceling be turn on however .  I have have to create a equalizer setting for they because they range seem a little odd . the low range on they be about right , but the mid be weak and the high be too strong . so its necessary to turn the high down , turn the mid up , and the medium-low range down . this be easy enough if youre use a computer with a equalizer that support preset . it might not be so easy with , say , a discman or something similar .  second , somebody review this unit and say that they `` pinch '' a little and that the ear muffle be shape incorrectly for human ear . this be mostly correct . because the unit fold in half , there be a constant tension against you ear , which the pad on the phone do not really protect you from . I notice that take my glass off ease this pain in my ear . however , not have my glass on make use the computer futile . they get real uncomfortable after about two hour of use .  would I buy they again ? well , maybe , if the price be drop $ 20 , and I have a chance to try out the Koss unit . otherwise , I think the only real reason to purchase they be so you can wow you friend and tell they they have noise canceling . hardly worth $ 110 for that .