The in-ear headphones with a rubber membrane will be excellent to

- isolate you from external noise

- isolate your co workers from your music (a problem with most alternative designs of headphones)

And if you listen to classical music, you are unlikely to suffer any hearing loss. And I find it to be perfect to focus on something in noisy environment (used them when I wanted to focus on something on a trading floor for years).

http://en-uk.sennheiser.com/earphones-headphones-sound-isola...