The advantage of in-ear without the inconveniences ....

Its specific tips - and I think Sony is the only company to offer this type of solution - it possible to project the sound to the inner ear almost like silicone tips to models ... but without the sometimes unpleasant pressure that sometimes inflict these. While the isolation level is a bit lower, but it is much more efficient than conventional headphones, which, moreover, are the main culprits of "sound leakage" so unpleasant for neighbors in the public transport.

In terms of the frequency response range, specifications 8-23000 Hz are among the best. Further down the first digit, deeper bass. I have Panasonic whose range is 6 to 23,000 Hz and barely was awarded the difference. And Sony are not yet running smoothly.

Only downside - I find the matter of a little unpleasant cord to touch, but I guess it happen with a little wear. The cord is a bit short for use with a laptop; If this concerns you, you can easily find a not too long extension on this site.