Issues to be aware of while wearing headphones

You can damage your hearing.

When you sit directly on top of a diesel engine for 90 minutes a day (commuting), it's tempting to crank up your walkman to dangerous levels. The earbud is contraindicated for any high-noise settings.

I would recommend BIG headphones, like your daddy has. This allows you to block out loud background noise, and use a lower volume.

As a low cost alternative, Koss has earplug-style earbuds which look like standard earbuds (and won't mess up your hair!). However, they have squishy foam that contours to your ear canal, blocking ambient sound.

If you think you've damaged your hearing, consult a professional:

The Lee Ranaldo (of Sonic Youth) Hearing Test

Set the volume of your radio to a level where you can barely hear the words. A talk show works best, as sometimes it is hard to understand lyrics in music. After [listening to loud music], turn on the radio to the same setting. Can you still hear and understand the words? If not, you're experiencing a form of short term hearing loss called temporary threshold shift. When this happens too many times, the damage can become permanent.
Emphasis added by me.

Sources: www.headwize.com (Ching!); www.fixup.net; www.koss.com