Any time sound information is prevented from reaching the brain due to damage, blockage, or other dysfunction of the ear, hearing loss results. Hearing loss is classified into three types: conductive, sensorineural and mixed. The type of hearing loss you have depends on which part of the ear is damaged, blocked or dysfunctional.
Conductive Hearing Loss
Conductive hearing loss occurs when the issue within the ear organ causing hearing loss is in the outer or middle ear. A sound wave’s journey from ear to brain begins at the outer ear and is directed into the middle ear. The outer ear consists of the ear canal and eardrum. The zone known as the middle ear begins on the other side of the eardrum, and it consists of three bones: the malleus, incus and stapes. These three bones are the tiniest bones in your whole body, and they amplify and conduct the sound wave deeper into the ear organ.
Causes of Conductive Hearing Loss
Possible dysfunctions of the outer and middle ear that could lead to hearing loss include:
- Compacted earwax
- Foreign object lodged in the ear canal
- Ruptured or perforated eardrum
- Fluid buildup due to a middle ear infection
- Bone abnormalities, such as otosclerosis
- Ear tumors
- Trauma or injury to the ear or head
Treating Conductive Hearing Loss
Most of the listed potential causes are physical obstructions that block the sound wave from traveling deeper into the ear. Also, in many of these cases, hearing loss is temporary and returns to normal when the underlying condition is resolved, such as when compacted earwax is removed or an ear infection clears up. Other cases, such as otosclerosis or an ear tumor, may require medical attention, but hearing will still return once that is completed.
In other cases, hearing devices can help with conductive hearing loss. Bone-anchored hearing devices and cochlear implants bypass the damaged outer and middle ear to send sound directly to the inner ear or auditory nerve, effectively treating conductive hearing loss.
Sensorineural Hearing Loss
Sensorineural hearing loss is the most common type of hearing loss. It is caused by dysfunction of the inner ear or nerve pathways that conduct sound information to the brain. The inner ear houses an organ called the cochlea, in which bundles of tiny hair-like sensory cells detect sound vibrations and code them into electrical signals. The cochlea then sends these electrical signals via the auditory nerve to the brain, where they are perceived as sound.
Causes of Sensorineural Hearing Loss
Most commonly, sensorineural hearing loss occurs when the hair-like sensory cells in the cochlea are damaged. These delicate cells do not regenerate, so all damage is permanent. It can also occur when the auditory nerve is damaged. Some ways these can happen include:
- Aging cells deteriorating naturally over time
- Exposure to loud noise
- Some medications, known as ototoxic drugs
- Disease
- Autoimmune disorders
- Cardiovascular issues, such as hypertension
- Diabetes
- Trauma or injury to the ear, neck or head
Treating Sensorineural Hearing Loss
Sensorineural hearing loss is typically treated with hearing aids. Hearing aids amplify sounds that enter the outer ear so the damaged cochlea can better detect them. Sensorineural hearing loss is not treatable with surgery or medication.
Mixed Hearing Loss
As the name suggests, mixed hearing loss is a combination of conductive and sensorineural hearing loss. This usually occurs when damage has occurred to the inner ear as well as the middle or outer ear. For example, a traumatic head injury could cause serious damage to the outer, middle and inner ear, or an antibiotic taken to treat an ear infection (which is causing conductive hearing loss) could be ototoxic and cause sensorineural hearing loss.
Treatment will vary with mixed hearing loss, as there are many scenarios with varying potential impacts on your ear’s function. Your audiologist will work with you to develop a treatment plan that suits your needs.
Treating Hearing Loss
No matter what type of hearing loss you have, our team at Hearing Services of Santa Barbara is experienced in diagnosing and treating it. Call us today to learn more and begin your treatment journey.