Hearing loss can occur for various reasons, ranging from age-related changes to injury or illness. Understanding the underlying causes is crucial for effective management and prevention. Below are the common causes of hearing loss:

1. Age-Related Hearing Loss (Presbycusis)

As we age, the structures of the ear naturally change, which can lead to hearing loss. Age-related hearing loss is typically gradual and affects both ears. It is more common after the age of 60 and often involves the high-frequency sounds first.

Contributing factors include:

• Wear and tear on the hair cells in the inner ear, which are responsible for transmitting sound signals to the brain.
• Changes in the auditory nerve and brain’s ability to process sound.
• Genetic predisposition and environmental factors such as long-term noise exposure.

Symptoms:

• Difficulty hearing high-pitched sounds (like birds chirping or a phone ringing).
• Trouble understanding speech, especially in noisy environments.
• A need to turn up the volume on televisions or radios.

2. Noise-Induced Hearing Loss (NIHL)

Exposure to loud noise over time, or a single instance of very loud sound, can damage the delicate structures of the inner ear, leading to hearing loss. This condition is common in occupations involving loud machinery, music, or construction, as well as recreational activities like attending concerts.

Causes:

• Prolonged exposure to sounds at or above 85 decibels (e.g., lawnmowers, construction equipment, or loud music).
• Sudden loud noises, such as explosions or gunshots, which can cause immediate damage to the ear structures.

Symptoms:

• Difficulty understanding speech, especially in noisy environments.
• Tinnitus (ringing in the ears).
• A feeling of fullness or pressure in the ear.

3. Middle Ear Disease

Diseases affecting the middle ear can lead to conductive hearing loss, where the sound cannot be transmitted effectively to the inner ear. This type of hearing loss is usually temporary but can become permanent if left untreated.

Conditions include:

• Otitis Media (Middle Ear Infection): Inflammation or infection of the middle ear, often causing fluid build-up.
• Otosclerosis: A hereditary condition in which the bones of the middle ear become stiff and do not move properly, impairing sound transmission.
• Tympanic Membrane Perforation: A tear or hole in the eardrum, which can result from trauma, infection, or loud noise.

Symptoms:

• Ear pain or pressure.
• Hearing loss, especially in one ear.
• Fluid drainage from the ear.
• A feeling of fullness or blockage in the ear.

4. Sudden Hearing Loss (Sudden Sensorineural Hearing Loss – SSHL)

Sudden hearing loss is an unexplained, rapid loss of hearing that occurs within 72 hours. It typically affects one ear and is considered a medical emergency, requiring immediate attention.

Possible causes include:

• Viral infections, such as those affecting the inner ear or the auditory nerve.
• Autoimmune conditions, where the body mistakenly attacks the inner ear.
• Vascular problems, such as a lack of blood flow to the ear.
• Trauma, such as a head injury.

Symptoms:

• A sudden, significant loss of hearing in one ear.
• Tinnitus (ringing in the ear).
• A sensation of fullness in the ear.

5. Dementia-Related Hearing Loss

Cognitive decline, including dementia and Alzheimer’s disease, can contribute to hearing loss or difficulty processing sound. Although dementia does not directly cause hearing loss, individuals with cognitive impairment may have trouble responding to auditory stimuli, or their hearing abilities may decline due to age-related changes.

Contributing factors:

• Age-related changes affecting both hearing and brain function.
• Difficulty processing sound, even if hearing is intact.
• Hearing loss may exacerbate cognitive decline, as individuals may become socially isolated or less engaged, contributing to faster cognitive decline.

6. Congenital Hearing Loss

Congenital hearing loss refers to hearing impairment that is present at birth. It can be caused by genetic factors or complications during pregnancy or birth.

Causes include:

• Genetic Factors: Many cases of congenital hearing loss are hereditary, either inherited from parents or arising due to genetic mutations.
• Infections during Pregnancy: Infections like rubella, cytomegalovirus (CMV), or toxoplasmosis during pregnancy can cause hearing loss in the child.
• Prematurity or Birth Complications: Babies born prematurely or with complications during birth may be at higher risk for hearing loss.

Ototoxic Medications: Certain medications, when taken during pregnancy or after birth, can damage the inner ear, resulting in hearing loss.