Hearing protection 101: The anatomy of the ear and how we hear

Unlike many workplace hazards, noise is invisible — and that makes it easy to underestimate. Hearing loss doesn’t happen in a single moment; it develops gradually and silently, often going unnoticed until permanent damage has already occurred. With nearly 22 million U.S. workers exposed to hazardous noise each year, it’s no surprise that hearing loss is now the nation’s third most common chronic physical condition. And unlike other injuries, once hearing is gone, it doesn’t come back.

To fully understand the risks, it helps to know how the ear works and why proper protection matters. By recognizing how noise impacts hearing in both the short and long term, safety managers and workers alike can better appreciate why consistent use of hearing protection is essential every single day.

How do our ears hear sound?

Hearing is what helps us connect with the world — allowing us to recognize objects, understand our surroundings, and communicate with one another through sound. But the way your ears process sound can directly impact your health. Prolonged exposure to hazardous noise can lead not only to hearing loss but also to a range of related issues, which is why consistent hearing protection is so critical.

So, how exactly does hearing work? It all comes down to a series of intricate steps that transform sound waves in the air into electrical signals your brain can interpret.

What's the structure of the inner ear?

All the structures of the ear work together to help you hear, starting from the outside. The outer portion of the ear is formed by the pinna, which is connected directly to the eardrum via the ear canal. The ear canal leads to the eardrum and is connected to the ossicular chain, which consists of three small bones: the malleus, incus, and stapes.

All of these hearing “aids” are located in the middle ear, where the stapes footplate is connected to the oval window of the cochlea. Here, signals are then transmitted to the auditory nerve.

What's the auditory nerve?

For hearing to occur, sound must travel through the air and be transmitted into the fluid-filled cochlea of the inner ear. Because fluids are much denser than air, this conversion is essential — without it, sounds would seem far quieter, and our perception of the world through hearing would be greatly diminished.

Here’s how your ears allow you to hear:

1. Sound enters via the outer ear and travels down into the ear canal before reaching the eardrum.
   
2. Here, vibrations are then directly passed on to the malleus bone. A chain reaction follows, with the malleus sending the signal to the incus, where it is then passed on to the stapes and the stapes footplate. Since the acoustic signal gradually travels from the eardrum's relatively large surface area to the very small stapes footplate, the signal is amplified step by step.
3. Next, the inner ear fluid is made to vibrate. Many little hair cells called stereocilia act as sensory receptors within the cochlea with two important functions: strengthening the sound wave even further and being responsible for our ability to differentiate between different frequencies.
4. Connected to the cochlea is the cochlear (or auditory) nerve, which sends these signals to the brain, where they are experienced as sound.

This set of events enables us to understand speech and distinguish various letters or words. The way your ears perceive sound can affect your health, both in hearing loss and in related issues, if sound levels are high enough.

The function of hearing and the impact of hearing loss

Hearing allows us to detect and interpret sounds from our environment so we can respond appropriately. When this function is impaired – whether due to age, noise exposure, or other factors – it can have serious consequences at work and at home.

The reality is that hearing loss doesn’t just affect your ears; it can influence nearly every aspect of daily life.

Take these examples below:

HexArmor® can help

Choosing the right earplug or earmuff technology depends on several factors – from your work environment to the level of noise exposure. HexArmor® makes this easy by offering a range of hearing protection solutions along with expert safety guidance, ensuring you get the right fit and the right protection for your specific job and environment.

Let us know if you need help finding what you need or if you're ready to start a trial - our Solution Specialists are ready to work with you. Call 1-877-MY ARMOR or send us a message.

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[Blog originally published on February 8, 2021]