Ear Physiology

• Your ear includes the inner and outer ear, separated by the eardrum. Outside, the pressure in the atmosphere is at work, but in the inner ear, it can take some time for pressure to equalize when atmospheric pressure changes rapidly. When this happens, you are more aware of the changes happening within your ear. The eustachian tubes--small, hollow tubes that connect your ears and throat--open up to allow the pressure to equalize. If the pressure difference is significant, you hear a "pop" as this process occurs.
  
  

Scenarios That Cause Ears to Pop

• The most common situation causing ears to pop is the rapid change in pressure that you experience as an airplane ascends or descends. The air pressure in the atmosphere is much lighter than on the ground, and the cabin is maintained at a constant pressure that is approximately equal to the pressure at 8,000 feet. The process occurs so quickly that your ears have a difficult time adjusting, thus, the pop.
  
  Other situations can make your ears pop as well. For instance, some people report that their ears pop when driving through the mountains or when traveling by train underground at rapid speeds. Those with particularly sensitive ears may even hear a pop as they travel in the elevator of a particularly high building.
  
  

How to Deal with the Popping

• If you are not congested, your ears will pop naturally, but it can be uncomfortable to wait for that process to occur. You may have noticed that some people chew gum or suck on hard candies as planes take off. The process of swallowing or chewing activates the muscles of the jaw, and since they are so close to the eustachian tubes, this can be helpful in equalizing the pressure. For small children and infants, sucking on a bottle or pacifier or breastfeeding during takeoff and landing can have the same beneficial effect.
  
  Some people hold their noses and mouths closed and attempt to blow, which does force air through the eustachian tubes, although some experts say that this can cause an ear infection if you are congested. If you do have a head cold, you should take a decongestant before flying or engaging in other activities that might cause your ears to pop, as the congestion can make it difficult to equalize the pressure and, in some cases, can even lead to damage to your ear drum.