I guess the measurements are taking into account only the portion of the sound which goes into the ear, otherwise the results would be incomparable. What is the point to look at the leaked part of the output? It is just a waste nobody is listening to the leaking sound from the headphones unless they are forced to do by someone who made a bad headphones choice))) I never said you are to look for the leaked sound on measurements. I was pointing out the reason for it. Open headphones have smoother bass and more neutral sound while closed back tend to have boosted bass.