The ear has three parts: outer, middle, and inner ear. The type of hearing loss you may have depends on what part (or parts) of your ear have damage. Hearing tests can tell you which type of hearing loss you have. They can also tell you the best treatment for your type of hearing loss. There are three main types of hearing loss: sensorineural, conductive, and mixed. Auditory neuropathy spectrum disorder is a fourth type of hearing. This is less common than the other three.
Sensorineural hearing loss
The inner ear helps with both hearing and balance. It contains fluid and thousands of tiny hair cells inside. We hear sound when these hair cells move. They transform the vibrations into electrical signals that your brain interprets as sound. Different hair cells move with different sounds. When these hair cells or nerves become damaged, sensorineural hearing loss occurs. This is the most common form of hearing loss.
Sensorineural hearing loss is permanent. There is no way to repair the damaged hairs. It generally affects both ears, though not always in the same way. Hearing aids are usually beneficial to patients with this type of hearing loss.
There are many causes of sensorineural hearing loss. Aging and chronic exposure to noise are the biggest culprits. Most common causes include:
- Noise exposure, particularly loud noises
- Genetic predisposition (hereditary hearing loss)
- Head injury
- Structural malformation of the ear(s)
- Ototoxic drugs (drugs that are toxic to the ears)
Presbycusis is the most common cause of sensorineural hearing loss. The natural aging process causes this. It happens over time and affects the ability to hear high pitched sounds. Presbycusis is progressive, and it affect 30 to 40 percent of people over age 65. Noise-induced hearing loss can compound the effect of presbycusis. Hearing aids may help with this type of hearing loss.
Sudden onset sensorineural hearing loss occurs in a quick manner or over a few days. This type of hearing loss requires immediate medical attention. Go see an otologist, a doctor specializing in ear diseases. Any delay may lower the chances of effective treatment.
Conductive hearing loss
The middle ear starts at your eardrum at the end of the ear canal. The eardrum moves with sound, and different pitches (high or low sounds) make the eardrum move less or more. The eardrum also makes the bones (ossicles) within it move, which sends a signal to the inner ear.
Conductive hearing loss occurs when noise can’t go through the outer and middle ear. This makes soft sounds hard to hear and loud sounds seem muffled. It can affect one or both ears. Conductive hearing loss is not permanent and medicine or surgery can repair it.
This type of hearing loss has many different causes, including:
- Otitis media (middle ear infection)
- Hole in the eardrum, such as a rupture
- Benign tumors
- Fluid in the middle ear from allergies, cold or flu viruses
- Earwax (cerumen) buildup
- A foreign object stuck in the outer ear
- Eustachian tube dysfunction
- Structural malformation of the ear(s)
Mixed hearing loss
This type is what it sounds like – a mix of both sensorineural and conductive hearing loss. There may be damage in the outer or middle ear and the inner ear at the same time. Having both types of hearing loss can make hearing loss worse than with only one of these types.
Causes include the same common causes for both sensorineural and conductive hearing loss. How does this type of hearing loss occur? A ruptured eardrum from an ear infection may be to blame. Working around loud noises for a long time can also cause this. Hearing aids may be beneficial for mixed hearing loss.
Auditory neuropathy spectrum disorder
Auditory neuropathy occurs with damage to the inner ear or the hearing nerve. This causes the brain not to understand normal sound entering the ear. The inner hear detects sound, but cannot send it to the brain.
This type of hearing disorder can affect people of any age. It is unknown how many people have this. Researchers believe auditory neuropathies play a large role in hearing loss.
Degrees of hearing loss
Regardless of type, hearing loss has many degree levels ranging from mild to profound.
Mild hearing loss results in soft sounds being hard to hear, though you can hear most speech sounds.
Moderate hearing loss is not understanding when someone is talking at a normal level.
Severe hearing loss results in not hearing any speech at a normal level and only some loud noises.
Someone experiencing profound hearing loss will be unable to hear any speech. They will only hear very loud sounds.
Other hearing loss definitions
Hearing loss uses many other clinical descriptions. They use these for further classifications. These include:
- Unilateral: hearing loss in one ear
- Bilateral: hearing loss in both ears
- Pre-lingual: happened before a person learned to talk
- Post-lingual: happened after a person learned to talk
- Symmetrical: loss is same in both ears
- Asymmetrical: loss is different in each ear
- Progressive: occurs over time
- Sudden: happens quickly
- Fluctuating: gets better or worse over time
- Stable: stays the same over time
- Congenital: present at birth
- Acquired or delayed onset: appears later in life
If you think you have hearing loss, make an appointment today. We can tell you the severity of your hearing loss and teach you about your hearing aid options. Request an appointment today!