If you care about your ears and don’t want to be one of those old folks who needs to have things repeated four times before they understand it, you really shouldn’t listen to regular headphones in places like airplanes or subways. The engine noise in these places is so loud that it forces you to blast your music to hear it over the roar, which does a number on your poor ears.
What you need is a pair of noise-canceling headphones, such as these Audio Technica ATH-ANC7 QuietPoint Active Noise-cancelling Headphones. They work by taking the low-end sounds that come from airplane engines and subway tunnels and creating frequencies that are exactly opposite. They cancel each other out, allowing you to listen to your music at normal volume without needing to compete with the surrounding noise. They even work when no music is playing, giving you a nice bubble to be in if you want to attempt a nap on an airplane.