How To Protect Your Hearing

As an audio engineer, I think about my hearing health every day. I believe anyone working in music should do the same. The following is a guide I’ve put together about maintaining and preserving your hearing. Nothing here should be interpreted as medical advice. You should always talk to your doctor or audiologist if you have any questions or concerns about hearing heath and hearing loss.

ANATOMY OF THE HUMAN EAR

The human ear has three main sections: the outer ear, the middle ear, and the inner ear. The outer ear includes the pinna (the structure on the outside of our heads) and the portion of the ear canal before the tympanic membrane (eardrum). The middle ear refers to the tympanic membrane and the portion of the ear behind it, including the ossicular chain (tiny bones that conduct sound pressure fluctuations to the inner ear). Finally, the inner ear includes the vestibular apparatus and the cochlea which converts mechanical pressure fluctuations to electrical signals that can be interpreted by the brain as sound.

TYPES OF HEARING LOSS

There are three main types of hearing loss humans can experience: conductive hearing loss and sensorineural hearing loss, and mixed hearing loss.

Conductive hearing loss refers to hearing loss that arises from an issue with the outer or middle ear. This could be caused by a buildup of wax in the outer ear, an ear infection, a ruptured eardrum, a breakdown of the ossicular chain, etc. Conductive hearing loss is often treatable/reversible.

Sensorineural hearing loss refers to problems with the inner ear and/or auditory nerve which transmits signals to the brain. This can be caused by aging, certain ototoxic medications, and quite commonly, noise exposure. Noise-induced sensorineural hearing loss can arise from a single “threshold shift” event (think loud concert, car horn, gunshot), or can accumulate over time after prolonged noise exposure (think working on a song too loud for too long over the course of a day). As of April 2023, sensorineural hearing loss is permanent and irreversible.

Mixed hearing loss refers to a combination of both conductive and sensorineural loss.

NOISE EXPOSURE GUIDELINES

OSHA (Occupational Safety and Health Administration) recommends different timed exposure limits based on varying sound pressure levels. The higher the SPL, the less time you should spend listening. Because the decibel scale is logarithmic, each addition of 3db represents a doubling of perceived loudness, meaning 70dB SPL is twice as loud as 67dB SPL is twice as loud as 64dB SPL, and so on. Included below are the OSHA and NIOSH noise exposure guidelines and a chart which contextualizes these various sound pressure levels.

PREVENTING SENSORINEURAL HEARING LOSS

While noise-induced sensorineural hearing loss may not be reversible, it is preventable. Beyond avoiding loud noises and prolonged exposure, in my opinion, hearing protection is the best first step. In other words, get some earplugs! Of course, there are a zillion options on the market, so how do you know which ones to buy? I think the earplugs you buy should be tailored to fit your particular use case. Here are some common options:

• Foam earplugs: These are probably the most common earplugs on the market. They’re cheap, but must be inserted correctly or they won’t work. When used properly, they offer some of the best noise reduction on the market, but this comes at the expense of sound quality; foam earplugs tend to reduce high frequencies more than low ones, so the resulting sound can often be muffled.
  

• Pre-molded earplugs: These are a step up from foam earplugs. They’re reusable, easier to insert, and can offer more even attenuation across the frequency spectrum. For many users, this is a sweet spot.
  

• Custom-molded earplugs: These are ideal for anyone who is exposed to loud noise on a regular basis. They are customized by an audiologist to fit your ears perfectly and often come with swappable attenuation capsules for different amounts of noise reduction. Unfortunately, these can be pricey and need replacing every 3-5 years as your ear canal changes shape. Speaking from experience, the brand your audiologist contracts with to make the earplugs is quite important. I’ve had custom earplugs that are fantastic and others that were beat by a $2 pair of wax earplugs (both in terms of noise reduction and sound quality).

When evaluating your earplugs, you’ll want to make sure you have a proper fit. You should also test the earplugs for something called the “occlusal effect.” This is when an earplug doesn’t go deep enough into the ear, resulting in a trapped resonant chamber of air within your ear canal, which in turn causes internal sounds (like your voice) to become amplified.

WHEN SHOULD I WEAR EARPLUGS?

If you live in a city where loud or unpredictable noises are common, I don’t think you should leave the house without wearing earplugs. The sad truth is that car horns, slamming truck liftgates, sirens, trains, motorcycles, construction, etc., are all too common not to wear hearing protection. I recommend owning a pair of “daily-driver” earplugs with a minimal to moderate noise reduction rating (NRR). Maybe something around 10dB. With these, you can still have conversations and be alert to your surroundings, but you’ll be protected in the event of an unexpected loud noise. Some wireless earbuds also offer protection from sudden loud noises and are worth considering.

Beyond your everyday hearing protection, you MUST wear hearing protection any time you go to a loud setting like a concert. This should be non-negotiable. If you get to the venue and realize you forgot hearing protection, you should turn around and not go in until you have some. It’s not worth it, even “just one time.” For these kinds of settings, I recommend earplugs with a bit more reduction – maybe 20-30dB. If you have custom molds, this is where swappable attenuation capsules come into play.

IS THERE ANYTHING I CAN DO TO PREVENT HEARING LOSS BEYOND EXPOSURE AVOIDANCE AND EARPLUGS?

Yes! While there is little to be done for sensorineural hearing loss reversal, there is compelling evidence suggesting diets high in antioxidants may be effective at reducing the degree of hearing loss following a loud noise event. If you want to get hardcore about it, you may want to look into a supplement called n-acetylcysteine for this. Again, this is not medical advice and I am VERY wary of pushing supplements, so talk to your doctor first. There is some compelling research about emerging treatments, but so far not much (if anything) has been adopted in the clinical space.

Beyond that, I recommend taking a holistic approach to your hearing health. Sleep, diet, exercise, and hydration are all important for keeping things running smoothly and your hearing is no exception.

WHAT HAPPENS IF I EXPERIENCE HEARING LOSS AND MY HEARING ISN’T COMING BACK? Have you ever gone to a concert without hearing protection and noticed your hearing was muffled afterwards? This is called a hearing threshold shift, meaning your hearing becomes less sensitive (the threshold for auditory signal detection increases). These threshold shifts can be temporary or permanent. Although threshold shifts should be avoided altogether, if you notice a reduction in hearing sensitivity following a loud noise exposure and your hearing doesn’t improve within 12 to 24 hours, you should RUSH to a clinic equipped to administer an intratympanic steroid injection. Evidence has shown that those who suffer from sudden sensorineural hearing loss have the best outcomes when treated as soon as possible.

HOW OFTEN SHOULD I GET MY HEARING CHECKED? Ideally every year. Most insurance companies cover this service annually. Even if you think your hearing is fine, it’s still a good idea to go to the audiologist regularly to establish a baseline and catch any issues as they arise. When you go, your audiologist will likely perform the following tests:

1. Otoscopy: During this test, your audiologist will examine your outer ear and tympanic membrane for any physical problems like wax buildup or injuries.
   

2. Pure Tone Audiometry: During this test, your audiologist will play different frequencies at various amplitudes to evaluate your hearing sensitivity across the frequency spectrum. In my experience, most audiometry machines are only calibrated to 8kHz, but if you ask, your audiologist might offer testing up to 12kHz. Most audiologists will conduct the pure tone audiometry test both by transmitting sound through your ear canal and by using a method called bone conduction. By placing a transducer on your skull, the emitted sound will bypass your outer and middle ear structures, only getting picked up in the inner ear. If there is a discrepancy between the results, it may be an indication that you are experiencing conductive hearing loss.
   

3. Speech Testing: This is where your audiologist will play random words at different levels and ask you to repeat them. If you score below 85% comprehension, you may want to see if your audiologist recommends a hearing aid. Many people are reluctant to wear hearing aids, seeing them as markers of aging. The truth is, by kicking the can down the road and avoiding hearing aids when they are recommended, you could be accelerating your hearing loss. Untreated hearing loss has also been linked to cognitive conditions like dementia.
   

4. Tympanometry: This test is used to evaluate the health of your tympanic membrane and ossicular chain by adjusting the pressure in your ear and evaluating how your eardrum responds.
   

5. Acoustic Reflex Testing: Our auditory systems have a built-in protection mechanism that stiffens certain ear structures when they are exposed to loud noise, almost like a mechanical limiter (no, not an excuse to forego earplugs). Acoustic reflex testing is used to see whether that reflex is performing as expected. If not, it could be an indication of sensorineural hearing loss.
   

6. Distortion Product Otoacoustic Emissions (DPOE): Your ear is an amplifier. Any amplifier (no matter how good) imparts some harmonic distortion to the input signal. DPOE testing takes advantage of this phenomenon. Your audiologist will play two frequencies into your ears. If your cochlea is working properly, it should emit a third tone that can be detected by a measurement tool. If it doesn’t, that could be a sign of cochlear damage/sensorineural hearing loss in the particular frequency region being tested.

Your audiologist will determine which of these tests are necessary based on your medical profile. In my opinion, it’s worth doing them all. Again, even if you have no hearing concerns, a comprehensive evaluation will serve as an important baseline for future testing and comparison.

FURTHER READING...

If you're interested in learning more about ear anatomy, hearing mechanisms, and psychoacoustics, I HIGHLY recommend this conversation (led by mixer Andrew Scheps). If you'd like to keep up with the current state of hearing loss reversal research, you can follow the Hearing Restoration Project, an international research consortium dedicated to solving the problem of hearing loss.

IMAGE SOURCES (IN ORDER)

https://www.happyearshearing.com/anatomy-of-the-ear/

https://www.ifcassociation.com/safety/blog/occupational-noise-exposure

https://www.protoolreviews.com/understanding-sound-pressure-level-spl-decibel-scale-db/