Not much leakage as they are over ear closed type headphones. I especially like the extra headphone cables they include. Included are 3 cables. One 3 metre straight cable, 3 metre coiled cable and a 1.2 metre straight cable. All have 3.5mm jacks but one end is threaded so you can screw on the 6.3mm adapter also included. Comes with a nice carrying pouch too. I will be testing out different genres of music over the next few weeks and will give my verdict on them but so far so good. Note that the M50X comes with all accessories I mentioned. I believe the M40x and M50x are the only models with detachable cables. The M20x and M30x are hardwired in.