October is Protect Your Hearing Month

Why is it so important to protect our hearing? Of course, we need to protect our entire bodies from harm, but hearing takes center stage in many discussions of protection. Though other parts of our bodies are susceptible to injury or damage, something about the hearing process makes it particularly fragile. Each October we set aside the month to celebrate “Protect Your Hearing Month,” and this annual event is a great opportunity to consider what puts our hearing at risk. Let’s begin by looking at hearing sensitivity before considering the important steps you can take to protect yourself. You can also take the opportunity of “Protect Your Hearing Month” to encourage others in your life to protect themselves.  

Hearing Sensitivity

It turns out that the very thing that makes hearing possible also makes it susceptible to damage. When sound enters the ear canal, it is simply a wave of pressure in a sea of air particles. Just like ripples in a still pond, these waves of compression and rarefaction of the particles are a chain reaction of jostling particles against one another. The features of the inner ear work together to detect the slightest differences in these pressure waves and to transform them into something the brain can understand. Each moment along the path from the outside air to the brain is necessary to detect these nuances of pressure. 

When the air particles encounter the tympanic membrane or eardrum, they become amplified to a stronger audio “signal” of pressure. As these pressure waves travel further into the ear, that pressure is transmitted into a fluid-filled conical region called the cochlea. Waves of pressure have now moved from air particles to fluid particles. Tiny hairlike organelles, called stereocilia, wave in this fluid, and they open tiny holes that are sparked by waves of a particular size, or frequency. These cell clusters then generate a precise electrical signal that is carried through the auditory neural pathway to the brain. The brain receives the specific characteristics of that electricity as a meaningful unit for interpretation. 

What is most amazing about this process is that the chaotic process of air particles bumping against one another in the environment can be transformed into something as subtle as speech. We can tell the voice of one person from another over the telephone, and we can often detect the region where a person was born based on these subtle differences in pronunciation and accent. What a remarkable skill of the body to transform pressure into meaning!

Hearing Damage and Protection

The same sensitivity that makes it possible to understand what others are saying also makes hearing quite easily damaged. Specifically, those stereocilia are clusters of cells that only detect a specific frequency of sound. If they are bombarded with overpowering pressure waves, they can become bent, broken, or otherwise damaged. When these organelles are damaged, they do not grow back on their own, leading to permanent hearing loss. 

For these reasons, protecting your hearing is one of the most important bodily forms of protection to put into practice. Just like wearing a helmet when you ride your bike or knee pads when you play volleyball, you should wear hearing protection when you are in a risky situation. Extremely loud sound can be sufficient to damage hearing in an instant, but noise-induced hearing loss can also occur with somewhat loud sound for an extended time. If you are concerned about the noise level in a place, you can take a decibel reading with your smartphone to get a general sense of the risk. 

When in doubt, it is a good idea to wear a pair of disposable foam earplugs that attenuate the total noise level by 10 to 15 decibels. If you need more advanced protection, you can wear custom-fitted ear molds that allow some sounds to enter while keeping out the dangerous ones. Even louder settings might require noise-canceling earmuffs, helmets, or headsets. 

Take the opportunity this October to protect your hearing and to encourage your loved ones to do the same. The amazing ability of the ears and brain to perceive and comprehend the world should not be treated lightly