No doubt, you’re familiar with the sensation and sound of your ears popping when taking off in an airplane or driving up a steep hill. If you’re into swimming and diving, the same thing happens when you go deep underwater. This happens because our ears and the inside of our skulls are very sensitive to changes in air and water pressure. If you’re not careful, sudden pressure changes can damage hearing.
How Pressure Affects Your Ears
When sound waves enter your ear, they travel down the ear canal, strike the eardrum and then the vibrations from the eardrum are conducted through the middle ear to the cochlea. Your middle ear is a small chamber behind your eardrum, and it is filled with air. Like all pockets of air, it responds to air and water pressure.
Your middle ear has a mechanism for equalizing pressure: the Eustachian tubes. These hollow tubes connect the middle ear to the back of the throat and work like a pressure valve. The entrance to them is usually shut tight, but when pressure changes, they open for a quick moment—pop—to allow higher- or lower- pressure air from your throat to enter your middle ears.
What Happens When Your Ears Can’t Equalize Pressure
Have you ever driven up or down a steep hill with an empty plastic water bottle in your car? Did you notice that the bottle scrunched up or swelled up as the elevation (and subsequently, the air pressure) changed, and that if you opened the lid even slightly, it went back to normal? That’s basically what the air-filled pocket of the middle ear goes through when the Eustachian tubes open. If the Eustachian tubes can’t open for any reason, it can lead to a feeling of plugged-up ears, ear pain or even a ruptured eardrum.
How does this affect hearing? As mentioned above, vibrations from sound waves are carried through the middle ear; if the pressure is off, it can distort the vibrations and even move the eardrum, making things sound funny or lowering hearing thresholds. Additionally, if your eardrum is ruptured due to pressure issues, it can affect hearing as well.
How to Protect Your Ears
The best way to protect your ears when flying or diving is to manipulate your Eustachian tubes to equalize pressure, and to do this often. Here are some ways to do that.
The Valsalva Maneuver
Hold your nose shut with your fingers and exhale gently into your mouth, without opening your mouth. (If you’re diving and using a regulator in your mouth, block the regulator with your tongue.) You don’t need to blow hard. This may take some practice, but it forces air into your mouth and sinuses, and ultimately into your Eustachian tubes. Whether diving or flying, this method is usually effective at opening the Eustachian tubes, and it can be done quickly.
Work Your Jaw
You can also jostle your Eustachian tubes open by working your jaw around, as the jaw joint is close to the muscles used to control the opening of the Eustachian tubes. Chew, swallow, suck on a piece of ice or hard candy or move your jaw side to side; if you’re on an airplane, you may also try yawning (although yawning will work quite poorly if you’re diving).
Can I Wear Earplugs?
Wearing basic earplugs creates a new air pocket inside your ears, between the plug and your eardrum, and any air pockets will become susceptible to damage from changing pressure. Since there’s no way to equalize the pressure created by this new earplug-induced air pocket, it will certainly contract under pressure and cause problems, such as a ruptured eardrum, and it’ll do that even faster than it would if you weren’t wearing earplugs and couldn’t open your Eustachian tubes. Specialty pressure-equalizing earplugs for air travel exist, but generally speaking, they’re not safe, especially for divers.
If you have any other questions about hearing protection or how air and water pressure can affect the delicate systems in your ear, give us a call! We at The House Institute are knowledgeable in all things auditory and are here to help our community members protect their hearing.