system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When flying on a plane the pressure can cause the volume of my music/headphones to be reduced. If I turn it up to a "normal" volume, am I causing higher than normal damage to my ears or is the pressure actually blocking sound and reducing the impact to my eardrums?
gpt
Passenger aircraft are usually pressurized to about 8000' equivalent altitude. Three things can be happening here. The first is that the slightly reduced pressure causes your eardrums to flex outward, and if you have a blocked eustachian tube or otherwise do not fully equalize your middle ear space, the increased tension on the eardrum will reduce its sensitivity.  Secondly, sound attenuates with distance to a greater extent when the air pressure is lower. This is probably not an issue with headphones, but could be if you were trying to speak to someone at the far end of the cabin. Finally, the noise floor on a plane is significant, with engine, wind and cabin noises all contributing. As the apparent loudness of your program material is the difference between the signal level and the noise floor, it will seem less loud than if you were listening in a quiet room.