The ear consists of three parts:
- the outer ear
- the middle ear, and
- the inner ear
The Human Ear @ bilderzwerg /AdobeStock
To understand how hearing loss develops, it’s helpful to look at the structure of the ear. The human ear consists of the three parts mentioned above.
The outer ear comprises the auricle and the ear canal. The auricle captures sound waves from the environment and directs them through the ear canal toward the eardrum.
The middle ear contains the eardrum and the three ossicles: the malleus, stapes, and incus. When a sound wave strikes the eardrum, it begins to vibrate. These vibrations are amplified by the ossicles and transmitted to the inner ear.
The inner ear contains the cochlea, also known as the spiral organ. Here, highly specialized sensory cells convert mechanical vibrations into electrical signals. These signals are transmitted to the brain via the auditory nerve. It is only there that the impulses are recognized and processed as sounds and tones.
If the sensitive sensory cells in the inner ear are damaged or otherwise impaired, the brain can no longer interpret the signals correctly. In this case, hearing ability declines and hearing loss may develop.
Hearing loss can have various causes.
Experts distinguish between:
- Conductive hearing loss
- Sensorineural hearing loss and
- Sound-processing hearing loss
In this type of hearing loss, sound is not properly transmitted from the outer ear to the inner ear. The cause is usually a problem in the ear canal or middle ear.
This can have various causes:
Acute causes
- Blockage of the ear canal (e.g., due to earwax)
- Inflammation in the ear canal (infection or middle ear infection)
- Tear or perforation of the eardrum (e.g., from ear cleaning)
- Disruption of the connection between the ossicles (e.g., due to injuries in the middle ear)
Chronic causes
- Congenital conductive hearing loss (e.g., due to malformation of the outer ear, ear canal, or middle ear)
- Excessive bone growth in the ear canal
- Chronic middle ear infection
- Otosclerosis (fixation of the stapes due to inflammatory remodeling processes)
- Changes in the middle ear mucosa (e.g., due to chronic ventilation problems in the Eustachian tube)
- Narrowing of the ear canal (e.g., due to scarring or inflammation)
- Tumors in the ear canal
In sensorineural hearing loss, the disorder lies in the inner ear or the auditory nerve. In such cases, the sensory cells of the cochlea are often permanently damaged.
Acute triggers
- Sudden hearing loss
- Exposure to loud noise, when people are exposed to noise levels exceeding 140 decibels for an extended period, e.g., at loud concerts, in clubs, or at work
- Infections that also affect the inner ear (e.g., meningitis, AIDS, measles, or sepsis)
- Side effects of medications
- Damage to the inner ear (e.g., due to a skull fracture)
- Rupture of the membranes between the middle ear and the inner ear
- Stressful situations
Chronic triggers
- Congenital malformations
- Daily exposure to noise levels exceeding 85 decibels for several hours
- Various diseases (e.g., kidney and thyroid disorders or diabetes mellitus)
- Meniere’s disease (increased pressure in the inner ear, resulting in damage to the sensory cells)
Another type of hearing loss does not directly affect the ear, but rather the processing of signals in the brain. In this case, the disorder lies in the areas of the brain responsible for hearing.
There can be various causes for this as well:
Hearing loss can vary in severity. The degree is determined based on the measured hearing loss.
Hearing loss is considered present at around 20 decibels or higher. With mild hearing loss, those affected have more difficulty perceiving soft sounds and tones.
With more severe hearing loss, it becomes increasingly difficult to understand conversations or ambient sounds.
Very severe hearing loss can lead to deafness.
Woman with a behind-the-ear hearing aid @ studioworkstock /AdobeStock
If hearing problems occur suddenly and are accompanied by other symptoms such as pain or fever, you should see a doctor.
An ear, nose, and throat (ENT) specialist is the appropriate professional to consult. It’s also important to consult a doctor if you experience gradually worsening hearing loss. If the brain doesn’t receive the relevant auditory signals for an extended period, it loses the ability to process them. At that point, even hearing aids will no longer be effective.
Treatment always depends on the cause. If, for example, the ear canal is blocked by earwax, the doctor can clean it out.
If there is an infection, decongestants are often prescribed. Antibiotics may be necessary for bacterial infections.
If structures in the inner ear are permanently damaged, natural hearing ability usually cannot be fully restored. In these cases, assistive devices are used.
A hearing aid can significantly improve impaired hearing. Modern devices specifically amplify certain sounds and tones, making it easier to understand speech.
In cases of severe hearing loss, deafness, or total hearing loss, cochlear implants may also be used. These partially replace the function of the damaged sensory cells in the inner ear.
Managing hearing loss also plays an important role in everyday life. Support from family members and early access to assistive devices help many people with hearing loss continue to participate actively in life.
In many cases, it is possible to prevent hearing loss. Protecting your ears from noise is particularly important. Anyone who regularly listens to music through headphones should keep the volume at a moderate level. People who are frequently exposed to very loud music or machine noise should use hearing protection.
Earplugs can also help protect your hearing at loud concerts or in clubs. Such measures can often prevent hearing loss in later life.
When people suffer from hearing loss for a long time, it can have health and social consequences. Communication problems often lead those affected to withdraw from conversations.
Hearing problems can also have serious consequences for children. If children have persistent hearing loss, it can impair language development because they do not adequately perceive important sounds and tones as well as linguistic stimuli. Early diagnosis and treatment are therefore particularly important.
Studies show that untreated hearing loss can be a risk factor for dementia. The brain receives fewer auditory stimuli and is therefore less stimulated. For this reason, it is important to detect and treat hearing loss and deafness in adults at an early stage.
How can you tell if someone has hearing loss?
Typical signs include hearing problems, frequently asking people to repeat themselves, and difficulty following conversations in a group. Hearing loss may also be present if sounds seem muffled or if soft sounds are no longer heard.
What is the most common cause of hearing loss?
One of the most common causes is age-related hearing loss, also known as presbycusis. In this condition, the sensory cells in the inner ear are slowly damaged as a person ages.
When do you need a hearing aid?
A hearing aid is used when natural hearing is impaired by permanent hearing loss and the person is significantly hard of hearing in everyday life.
Can hearing loss be prevented?
Hearing loss can be partially prevented by protecting your hearing. This includes using hearing protection, earplugs, keeping the volume at a reasonable level when listening to music through headphones, and protecting yourself from loud noise.
