Hearing loss: Causes, diagnosis and treatment

Approximately 14% of adults have experienced some noticeable degree of hearing impairment, and the issue increases with age. Hearing is very important as it connects us with our family and friends and keeps us aware and safe during daily activities. Loss of hearing isolates us from our loved ones and contributes to depression and even dementia. It’s important to have your hearing checked. Many types of hearing loss can be treated with a proper diagnosis.

There are four categories of hearing loss, each associated with a different set of causes.

1. Conductive hearing loss: Hearing begins when sound travels from the outer ear into the middle ear, which consists of the eardrum and three small bones known as ossicles. Conductive hearing loss occurs when something prevents sound conduction through these areas. Possible causes include:

• Earwax buildup
  
• Accumulation of fluid in the ear due to allergies or a cold
• Inflammation from middle ear infections
• Inflammation from outer ear infections
• Problems with eustachian tubes, which can result in fluid building up
• Injury to the eardrum
• Tumors developing in the ear
• A foreign object becoming lodged in the ear
• Defects present at birth that impact the outer and/or middle ear

2. Sensorineural hearing loss: The most common type of hearing loss, sensorineural hearing loss occurs due to problems with the inner ear, which includes the cochlea, the semicircular canals that control balance, and nerves that carry information from the ear to the brain. Most often, sensorineural hearing loss develops slowly over time, but it can occur rapidly in some cases. Causes of sensorineural hearing loss include:

• Age-related changes to the inner ear
  
• Medical conditions, like hypertension, diabetes, stroke and heart disease
• Ototoxicity, when medication damages the ear
• Genetic conditions
• Head injuries
• Repeated exposure to loud noises
• Certain infections, such as cytomegalovirus (CMV)

3. Mixed hearing loss: When hearing loss is due to problems with the outer or middle ear and the inner ear, the problem is called mixed hearing loss. Mixed hearing loss often occurs due to more than one cause. For example, an older adult who has lost hearing due to age-related changes might rupture an eardrum, or someone who has lost hearing due to working in a noisy environment may develop a middle ear infection.

4. Auditory neuropathy: When hearing loss occurs due to problems with how the ear processes sound messages rather than by issues with how sound moves through the ear, the problem is usually diagnosed as auditory neuropathy. People with auditory neuropathy usually hear normally, but sound information produced by the ears gets encoded improperly, making it impossible for the brain to interpret correctly. This type of hearing loss may be caused by:

• Genetic abnormalities that impact the hair cells or auditory nerve
  
• Damage to the auditory nerve
• Damage to hair cells within the ear

The first step in diagnosing hearing loss is usually an ear examination with a handheld device called an otoscope. Based on the findings of the physical exam, a healthcare provider may order additional tests, such as:

1. Blood work
   
2. Imaging tests: MRIs and CT scans are types of imaging tests your provider may request
3. Pure-tone test: A hearing test that identifies the quietest sound that the ears can detect at various pitches
4. Otoacoustic emissions test (OAE): A hearing test that involves inserting a probe into the ear to monitor how ear hair cells function in response to sound
5. Tympanometry: A hearing test that assesses how well the eardrum functions
6. Auditory Brainstem Response (ABR) test: A hearing test that measures electrical activity in the nerves, which is usually performed on babies and young children

Once a hearing loss diagnosis is made, your healthcare provider will recommend treatments based on the root cause of the problem, the severity of the problem and your health history. Treatments vary based on the type of hearing loss, as follows:

1. Conductive hearing loss: To treat conductive hearing loss, a healthcare provider may recommend:

• In-office earwax removal
  
• Antibiotics to treat infections
• Surgical procedures to repair problems with the tubes of the ears or the eardrum
• Medications to treat any health conditions that may be contributing to hearing loss, such as blood pressure medications

2. Sensorineural hearing loss: When sensorineural hearing loss is caused by temporary inflammation in the inner ear, healthcare providers may prescribe corticosteroids. However, sensorineural hearing loss is often permanent, so management of the problem with hearing aids and other assistive devices is the most common treatment. For people with noise-related hearing loss, taking steps to protect the ears from further damage is an important part of treatment.

3. Mixed hearing loss: To treat mixed hearing loss, healthcare providers typically develop a treatment plan that includes medications or procedures for inner or outer ear problems, as well as medications and/or hearing aids for inner ear issues.

4. Auditory neuropathy: Cochlear implants and hearing aids are sometimes beneficial for people with auditory neuropathy. When these interventions don’t improve hearing, patients may learn sign language and receive speech therapy and other therapies to help improve their communication abilities.

Hearing loss needs to be addressed at all ages, and treatments have greatly improved over the past decades. Older adults, especially men, are reluctant to have their hearing checked. However, they often have the most to gain from treatments, including hearing aids.

If you’re experiencing hearing issues, start with your primary care provider, as some causes are easily treated. If your primary care provider sees fit, they may refer you to an audiologist, a healthcare professional who diagnoses hearing loss.

Updated August 2024.