Relax and Enjoy The Journey. Get Peaceful Silence (Or At Least Closer To It!)
With good travel headphones, whether it's plane, train, or automobile, the best travel headphones will isolate external ambient noise while providing a great music listening experience.
Other convenient features like full foldability, built-in smartphone mics, and durable carrying cases have contributed to the mass popularity of travel-oriented and noise-cancelling headphones for listeners riding the tracks or flying the friendly skies. Personally, we wouldn't want to travel any other way!
There are three general categories of travel-oriented headphones:
Noise-cancelling headphones are excellent train and airplane travel headphones. They are specifically designed to block the constant lower-frequency hum heard in an airline or train cabin as well as other steady background noises. The battery-powered noise-cancelling design typically provides around ~15dB to -25dB of isolation and usually employs a noise-canceling on/off switch with easily replaceable AAA or AA batteries housed inside the headphones.
In-ear headphones offer the most ambient noise isolation at around -20dB to -35dB. They can offer excellent sound quality and superb isolation (noise-blocking ability) in a small and convenient package. Many in-ear models have built-in smartphone mic capabilities. The best sealing in-ear headphones will provide better isolation than big noise-cancelling headphones, particularly in the upper frequencies (like loud human voices or crying babies!).
Closed headphones provide less isolation, usually around -10dB to -20dB for the larger cans, and are typically not quite as effective at isolating the lower 'rumble' frequencies typically heard in airplanes or other mass transit. On the upside, the best closed/sealed headphones can sound very good at attractive prices and can also function beautifully in other listening environments like a dorm room or office cubicle.