Privacy concerns, sound quality and overall experience are all factors that need to be considered. To this list we need to add portability. Sound cards, CD-ROM drives, and DVD drives are becoming common staple in laptops. Unfortunately, listening to your favorite music of may not be appropriate on long airplane flights. In the air, most laptop speakers are easily drowned out by the jet engines.
Headphones become the only solution.
The best headphones are unfortunately the biggest headphones. Earbud headphones have tried to solve this portability issue, although often at the expense of sound quality. Sennheiser, a world famous designer of headphones has taken on this challenge with its MX line of headphones. The top of the line model is the MX 5. Sennheiser as most of us know is synonymous with making great headphones.