A headset for outdoors

The name of the headset is the "Sennheiser CX 200 Street II In-Ear Headphones" program.
Since a significant noise can be heard in absolute silence, the headphones for the home are limited. Who thus lying on the couch or in bed and listening to music, is clearly heard a noise, especially in quiet passages. This can be a KO criterion.
If you use the headset, however, on the road, is through the ambient noise (which are pretty well reduced by the in-ear headphones), the noise is no longer audible, not even for audiobooks, where you, the noise due to the constant pauses even more perceives.
Ever intelligibility is wonderful even at low volumes on the road. I would not have expected that.
Nevertheless, there is a star deduction. The noise did not have to be.