Hearing Loss: Types, Causes, Symptoms, and Treatment Options

Hearing loss is defined as a reduction in the ability to perceive sounds. It is broadly classified into three main types. Recognising these different types and their causes is essential for proper diagnosis and effective treatment.

Conductive hearing loss

Conductive hearing loss occurs when there is a problem transmitting sound waves through the outer ear canal to the eardrum or the tiny bones of the middle ear. 

There is often a blockage or dysfunction in the outer or middle ear, which hinders the passage of sound. This typically leads to sounds being perceived as quieter than usual.

Common Causes Include:

• Ear Infections: Conditions like otitis media, where the middle ear becomes inflamed or filled with fluid, can obstruct sound transmission.

• Fluid in the middle ear: Colds or allergies can cause fluid accumulation in the ear, leading to temporary hearing difficulties.

• Earwax buildup: An excess of earwax can clog the ear canal, affecting the ability to hear.

• Structural abnormalities: Both congenital (present from birth) or acquired abnormalities in the ear's structure can disrupt the flow of sound.

Sensorineural hearing loss

Sensorineural hearing loss is due to damage to the inner ear (cochlea) or the auditory nerve pathways that connect to the brain. This form of hearing loss involves damage either to the cochlea or to the auditory nerve, resulting in a decrease in both the clarity and volume of sounds.

Causes Include:

• Age-related hearing loss (Presbycusis): As people age, the structures within the inner ear deteriorate naturally, making it harder to hear high-pitched sounds.

• Noise-Induced hearing Loss: Continuous exposure to loud noises—such as machinery, music, or firearms—can damage the cochlea's delicate cells. This type of hearing loss is usually permanent but can be prevented with adequate ear protection.

• Genetic factors: Some hereditary conditions can make individuals more susceptible to sensorineural hearing loss. Mutations that affect the inner ear or auditory nerve can cause congenital hearing loss or increase the risk of hearing impairment later in life.

• Certain medications (Ototoxic Drugs): Drugs known to be toxic to the ears, like some antibiotics or chemotherapy agents, can damage the structures of the inner ear, resulting in hearing loss.

Mixed hearing loss

Mixed hearing loss is a combination of both conductive and sensorineural hearing loss. This means there are issues in both the outer or middle ear and the inner ear or auditory nerve.

Causes: This type of hearing loss can occur when a person has a condition affecting the outer or middle ear, alongside an underlying problem in the inner ear or auditory nerve, such as a mix of ear infections and age-related hearing loss.

Other common causes of hearing loss

Hearing loss can stem from various factors, from natural ageing processes to external injuries. Understanding these causes is also crucial for both prevention and effective treatment:

• Ear infections and illnesses: Local infections like otitis media or systemic illnesses such as measles can either temporarily or permanently affect hearing by damaging the ear's structures or causing related complications.

• Trauma or Injury: Physical damage to the ear or head—resulting from accidents or impacts—can alter the ear's anatomy, leading to immediate or long-term hearing loss.

• Congenital Conditions: Hearing impairments present at birth, often due to genetic factors or complications during pregnancy, can lead to conditions like congenital deafness, which can be managed effectively with early intervention.

Hearing loss manifests in various ways, depending on its cause and severity:

• Gradual onset - Many individuals experience a slow decline in hearing ability, especially in noisy environments. Symptoms may include frequently asking others to repeat themselves and difficulty following conversations in crowded places.

• Sudden onset - A sudden decrease in hearing ability can occur, sometimes accompanied by a sensation of fullness in the ear. This may be due to an acute condition, such as sudden sensorineural hearing loss or an ear infection.

• Tinnitus - The ringing, buzzing, or hissing sounds in the ears, known as tinnitus, often accompanies hearing loss. This symptom can be persistent and may vary in intensity.

• Muffled hearing - Sounds may seem muffled or less distinct, making it challenging to hear clearly. This sensation can be due to a buildup of earwax or damage to the inner ear structures.

Treatment for hearing loss varies depending on its cause and severity:

• Hearing aids -  For sensorineural hearing loss, hearing aids can amplify sound and improve hearing. These devices are customised to meet individual needs and can significantly enhance communication.

• Cochlear implants - For individuals with severe hearing loss who do not benefit from hearing aids, cochlear implants may be recommended. These surgically implanted devices bypass damaged parts of the ear and stimulate the auditory nerve directly.

• Medical treatment - Addressing underlying conditions such as ear infections or removing earwax can alleviate conductive hearing loss. Medications or minor procedures may be required to treat these issues effectively.

• Surgery - Certain conditions causing conductive hearing loss, such as otosclerosis (abnormal bone growth in the middle ear), may be treated with surgical interventions to restore hearing.

Understanding these aspects of hearing loss can help recognise the condition, seek appropriate treatment, and improve overall auditory health.

Prevention of hearing loss

Taking care of your ears can help prevent hearing problems. Here’s what you can do:

Use ear protection such as earplugs or earmuffs when you’re around loud noises, like at concerts or on construction sites. This helps protect your ears from loud sounds that can damage your hearing. It's a good idea to have your hearing checked regularly, especially if you're older or have often been around loud noises. Regular checks help catch any hearing problems early. Taking care of your overall health is good for your ears, too. Avoid using medications that can harm your hearing, and keep your ears clean without using cotton swabs, which can push earwax deeper.

If you notice any of the following, it’s important to see a doctor:

• Persistent symptoms: If you’re having trouble hearing, and it doesn’t get better or worsen, see a doctor. There might be an underlying problem that needs treatment.

• Sudden hearing Loss: If you suddenly lose your hearing in one or both ears, get medical help immediately. Sudden hearing loss can be caused by several things that need prompt attention.

• Other symptoms: If you have hearing loss along with pain, dizziness, or fluid coming out of your ear, see a doctor. These symptoms can mean a serious issue that needs to be checked out.

Conclusion

Taking care of your hearing is important for your overall well-being. Protect your ears from loud noises, get your hearing checked regularly, and stay healthy. If you notice hearing problems or other symptoms, visit a doctor quickly. Early treatment can help you manage hearing loss and keep your ears in good shape.