Studies have shown that using earbuds or headphone in noisy places like on an airplane, train, or subway is bad for your ears. Be it there is so much background noise, the likelyhood of you turning the volume up higher is increased, which maybe too high.
Harvard researchers found that in quiet surroundings, people tended to keep the volume at an ear-friendly level. However, when background noise was added, 80% boosted the volume as high as 89 decibels, a level that risks long-term hearing damage. If you are like me, and need music, it is better to use noise-canceling headphones. Get a free pair here.