At an average size of just 2-1/2 inches long (larger with age), the ears are complex organs comprised of many small parts that all play a role in hearing and balance. Let’s delve into the anatomy of the ear to understand how the individual parts function, as well as what can happen within those parts to cause damage or hearing loss.
Here’s a quick overview of the anatomy of the ear:
- Outer ear
- Middle ear
- Inner ear
- Central auditory pathways
Keep reading for more details about these parts and how they affect your hearing.
In the anatomy of the ear, the outer ear is the part that is always visible. It consists of two sub-parts: the auricle (visible part of your ear) and the ear canal (tube leading inwards). This part of the ear exists to collect and funnel sound to the delicate interior workings. When sound waves enter the outer ear, the vibrations travel down the ear canal to the eardrum.
The outer ear is generally only subject to cosmetic damage, but one situation that can lead to temporary hearing loss or tinnitus here is a buildup of earwax in the ear canal. This buildup can have a muffling effect on the delicate structures inside. Fortunately, it is easy to fix with removal treatment.
Learn more about what you need to know about earwax here.
Next up in the anatomy of the ear is the eardrum, where the hearing mechanics of the ear truly start. It is an extremely thin membrane of skin that separates the outer and middle ear. When sound waves reach the eardrum, they cause it to reverberate, which triggers activity in the middle ear. The eardrum is also responsible for shielding the middle ear from water or bacteria that make it in from the outer ear.
The eardrum membrane is extremely delicate and can be vulnerable to damage. Ruptured eardrums are a common response to overpressure that can lead to hearing loss, including any situation with loud noises or extreme changes of pressure. Eardrums can also rupture if ear infections cause pressure buildup from fluids, so don’t delay a doctor visit if you’re having symptoms like earache, fever, congestion, or muffled hearing.
Foreign objects, like cotton swabs, can also damage or puncture the eardrum. Any form of hole or tear in the eardrum can cause severe pain could lead to hearing loss. In most cases, the eardrum will heal, and hearing will be restored. If you suspect a damaged eardrum, see your doctor or audiologist to ensure you receive proper care.
The middle ear is the “mechanical” section of the ear where a combination of moving parts and bio-electrical signals convert the vibrations of the eardrum into sound. The tiny movements of the eardrum are transmitted to the ossicles, three tiny, interconnected bones that convert the vibrations into mechanical movements. These bones are the smallest in the human body and are also extremely fragile (although they are less likely to suffer damage than the eardrum). These bones then pass this physical movement into the fluid-filled inner ear, to be processed further.
The middle ear also contains the opening to the eustachian tube, which connects the middle ear to the back of the throat and sinuses. The eustachian tube primarily serves to regulate the pressure behind the eardrum, but is often what causes an earache during ear, nose, and throat infections, and can be a vulnerable part of the anatomy of the ear susceptible to hearing damage.
Learn more about earaches and hearing loss here.
The inner ear is a fluid-filled space that functions for both hearing and balance, with a compartment for each. The hearing portion of the inner ear is a spiral structure called the cochlea. This snail-shaped section is made of bone and contains tiny hair cells that turn movement in the fluid into chemical signals, stimulating nerves that carry sound to the brain. This organ detects volume variations by registering the location and number of hairs affected by the movement and transmitting the appropriate information. Balance is controlled by the semicircular canals. The fluid within them provides information to the brain about how the head is rotated.
Damage to the inner ear is one of the most common causes of hearing loss. To some degree, it can occur as a natural part of aging. Over time, hair cells become damaged and make hearing more difficult. However, inner ear damage from exposure to high levels of noise can accelerate the potential to experience hearing loss.
Central Auditory Pathways
The central auditory pathways – or CAP, for brevity – are the neural pathways that travel from the anatomy of the ear to the brain. These pathways are vital to the brain’s ability to process sound. All of the information transmitted by the CAP is taken to different parts of the brain, to extract the maximum amount of information from the stimulus.
Though it is extremely rare, lesions on the CAP can cause central hearing loss. Sometimes this type of hearing loss is permanent, but medical and surgical treatments are available.
Exploring the anatomy of the ear and the potential for damage to its parts can help shed light on the causes of hearing loss. As always, if you have any questions on your ears or hearing, be sure to talk to your doctor. To help protect your ears, check out another infographic featuring hearing protection tips here and visit our blog for more articles on hearing loss today.