Your Guide to the Different Types of Hearing Loss

Hearing is a complex process that allows us to interpret and respond to the world around us. However, you can gradually lose this sense when any part of the auditory system stops working correctly. This condition becomes more prevalent as you age, specifically in your 60s and 70s.

There are several types of hearing loss, each with different causes, characteristics, and levels of severity. Only an audiologist or a qualified healthcare professional can properly diagnose the type of hearing loss a patient may have. They can tell you these distinctions and identify the right treatment through Canada hearing tests. However, it wouldn’t hurt to do your own research. In this blog post, we will understand the different types of hearing loss, their degrees of impairment, and ways to potentially determine your hearing loss type.

How Does Hearing Loss Take Place?

Hearing loss usually happens when the normal transmission of sound is disrupted at any point in the hearing pathway. Here’s how sound is normally processed:

1. Sound waves enter the ear canal and travel to the eardrum, causing it to vibrate.

2. Vibrations are amplified by the tiny bones (ossicles) in the middle ear, transmitting the sound to the cochlea.

3. Hair cells within the cochlea convert the sound vibrations into electrical signals.

4. These electrical signals are sent along the auditory nerve to the brain, where they are interpreted as sound.

Hearing loss occurs if the outer ear, middle ear, inner ear, or auditory nerve is damaged or compromised by disease, injury, noise exposure, or aging.

What Are the Different Parts of the Ear?

The ear is divided into three main sections:

• the outer ear

• the middle ear

• the inner ear

The outer ear includes the visible part of the ear and the ear canal. It collects sound waves and directs them inward. Meanwhile, the middle ear contains the tympanic membrane (eardrum) and three small bones (ossicles). These amplify sound vibrations and transmit them to the inner ear. Finally, the inner ear involves the cochlea and auditory nerve, which process sound vibrations into electrical impulses that travel to the brain.

Hearing loss can occur when any of these structures are affected by conditions such as an ear infection, a ruptured eardrum, damage to the hair cells, or medical conditions like otitis media or heart disease.

What Are the Different Hearing Loss Types?

Hearing loss is classified based on the part of the affected auditory system. There are five main types discussed below.

Age-Related Hearing Loss

One of the most common causes of hearing impairment is age-related hearing loss, also known as presbycusis. This typically occurs in older adults, with one in three people expected to have some type of hearing impairment between the ages of 65 and 74. It affects hearing high-pitched sounds and speech clarity, especially in noisy environments.

Gradual hearing loss as you age is usually caused by the following:

• Inner ear changes or degeneration of sensory cells

• Alterations in the middle ear and complex changes along the nerve pathways from the ear to the brain

• Long-term exposure to loud noises

• Chronic illnesses like high blood pressure and diabetes

• Certain medications toxic to sensory cells in the ears

Auditory Neuropathy Spectrum Disorder

Auditory neuropathy spectrum disorder (ANSD) affects how sound signals travel from the inner ear to the brain. While the cochlea may function properly, the auditory nerve fails to transmit electrical signals effectively. This results in difficulties recognizing speech sounds and fluctuating hearing ability.

Conductive Hearing Loss

When sound waves cannot properly travel through the outer and middle ear, it causes muffled hearing or conductive hearing loss. Damage to the outer ear canal, middle ear, or both can contribute to this hearing impairment. An ear infection, ruptured eardrum, fluid buildup, or an obstruction in the ear canal can also be culprits. Treatment options include medical intervention, surgery, or Canada hearing aids to improve hearing.

Sensorineural Hearing Loss

Sensorineural hearing loss is due to damage in the inner ear or auditory nerve. The most common cause is damage to the hair cells in the cochlea, often from aging, loud noise exposure, viral infections, or medical conditions like heart disease. Under this category is the sudden sensorineural hearing loss.

Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) is a rapid, unexplained loss of hearing, usually in one ear and occurring within a 72-hour period. Viral infections, autoimmune disorders, exposure to loud sounds, or even tinnitus can cause it. Prompt medical attention is necessary to prevent permanent damage.

Mixed Hearing Loss

Mixed hearing loss refers to a condition where a person experiences both conductive and sensorineural hearing loss simultaneously, meaning there are issues in both the outer/middle ear and the inner ear. In short, it is a combination of the two types of hearing loss. Treatment depends on the severity of both components and may involve a combination of surgery, hearing aids, or cochlear implants.

What Are the Other Types of Hearing Loss?

Hearing loss can also be categorized based on when and how it develops.

Congenital and Delayed Onset

Congenital hearing loss is present at birth, often due to genetic factors, infections during pregnancy, or complications at birth. Delayed-onset hearing loss develops later, sometimes due to exposure to loud noise or progressive medical conditions.

Pre- and Post-Lingual

Pre-lingual hearing loss occurs before a child develops speech, while post-lingual hearing loss happens after speech acquisition. Post-lingual hearing loss is easier to manage with hearing aids or sign language training.

High and Low Frequency

High-frequency hearing loss affects the ability to hear high-pitched sounds, such as speech consonants, while low-frequency hearing loss impairs the perception of deeper sounds. Both types impact speech comprehension in different ways.

Sudden and Progressive

Sudden hearing loss happens rapidly, often within hours or days, whereas progressive hearing loss worsens over time due to aging, noise exposure, or a medical condition.

Stable and Fluctuating

Stable hearing loss remains constant over time, while fluctuating hearing loss varies in severity. Fluctuating hearing loss is often linked to medical conditions like Ménière’s disease.

Symmetrical and Asymmetrical

Symmetrical hearing loss affects both ears equally, whereas asymmetrical hearing loss affects one ear more than the other. Identifying this distinction is crucial for determining treatment.

Unilateral and Bilateral

Unilateral hearing loss affects only one ear, making it difficult to determine the direction of sounds. Bilateral hearing loss affects both ears and may require hearing aids in both ears to improve hearing.

What Are the Different Degrees of Hearing Loss?

Hearing loss varies in severity, affecting an individual’s ability to detect soft sounds and speech clarity.

Profound

Profound hearing loss means a person can only hear very loud sounds, such as an airplane taking off, and often requires cochlear implants or other advanced solutions.

Severe

Severe hearing loss makes it difficult to hear normal speech. Without amplification, only very loud sounds are audible.

Moderate

Moderate hearing loss affects the ability to hear speech at a normal level. Conversations in noisy environments become challenging without hearing aids.

Mild

Mild hearing loss makes hearing soft sounds, such as whispers, difficult, but speech is generally understandable in quiet settings.

Slight

Slight hearing loss is the least severe and may not require intervention, but subtle difficulties in perceiving certain speech sounds may arise.

Determining Your Type of Hearing Loss

A hearing test or audiometry conducted by an audiologist can determine your type of hearing loss. This test measures the extent of hearing loss, followed by further investigations like blood tests, imaging (MRI), or vestibular testing to explore possible underlying causes.

Here’s how a test is usually performed:

1. The audiologist places a device behind your ear or on your forehead.

2. The device sends sounds that make your skull vibrate.

3. The vibrations travel to your inner ear, bypassing your outer and middle ear.

4. The audiologist compares the test results to determine the type of hearing loss.

Additionally, a hearing test result could show the following:

• Degree of hearing loss (How loud sounds need to be for you to hear them)

• Type of hearing loss

• Affected tones (Which tones are affected by the hearing loss)

Conclusion

Hearing loss affects people (adults mostly) differently, depending on the underlying cause and severity. It can happen through age-related changes, noise exposure, or a medical condition. Recognizing the signs and seeking professional evaluation is key to managing and improving hearing. Technology advancements, including cochlear implants and hearing aids, provide options for those experiencing hearing impairment. Protecting your hearing and addressing any concerns early can help preserve your ability to hear speech, music, and everyday sounds for as long as possible.