Types of Hearing Loss
There are five types of hearing loss:
- Conductive: Sound waves are not able to pass through the outer and/or middle ear to the inner ear for processing.
- Sensorineural: Caused by damage to the tiny hairs within the cochlea in the inner ear; sound is unable to be converted into electrical signals for the auditory nerve.
- Mixed: A combination of conductive and sensorineural hearing loss.
- Neural: A result of damage to the auditory nerve that connects the cochlea to the brain.
- Auditory Neuropathy: Sound enters the ear normally, but the transmission from the ear to the brain is impaired.
Conductive Hearing Loss
Conductive hearing loss occurs when there is a condition of the outer or middle ear that prevents sound from reaching the inner ear. Causes can include blockage of the outer ear or ear canal, an ear infection with fluid, or a malformation of the outer or middle ear. In some cases, conductive hearing loss may be temporary or treatable with medication or surgery. If the condition cannot be addressed through medication or surgery, many people with conductive hearing loss may benefit from using traditional hearing aids or bone conduction hearing aids .
Sensorineural Hearing Loss
Sensorineural hearing loss is usually a result of a problem with the cochlea, either through malformation or damage. Damage can occur from infections such as meningitis, or as a side effect of certain medications described as ototoxic (meaning they are toxic to parts of the ear). Ototoxic medications are provided under extreme circumstances and with medical consultation with the patient and/or family as to their risks.
Sensorineural hearing loss cannot be treated with medication, and some options include traditional hearing aids, middle ear implants or cochlear implants . Options vary depending on the cause and severity of the hearing loss. Consult your otolaryngologist (ear, nose and throat physician) and audiologist to discuss an appropriate course of action.
Mixed Hearing Loss
Mixed hearing loss is a combination of conductive and sensorineural hearing loss. The causes and options are the same as those described above.
Neural Hearing Loss
Neural hearing loss is rare and is the result of damage or malformation to the auditory nerve. Neural hearing loss is usually profound and permanent. Traditional treatment options like hearing aids or cochlear implants are not viable because the auditory nerve is not able to transmit information to the brain. In some cases, auditory brainstem implants have been utilized with limited success.
Auditory neuropathy occurs when sound travels through to the inner ear normally, but the transmission of the auditory signals to the brain is impaired. Auditory neuropathy can affect children and adults, however incidences are low. People with auditory neuropathy generally have mild to severe hearing loss, and they always have poor speech perception no matter what level of hearing loss they have. Auditory Neuropathy can be very difficult to diagnose, especially in children when their hearing abilities appear to change back and forth. For more information on auditory neuropathy visit the National Institute on Deafness and Other Communications Disorders website.
Note:Some individuals with hearing loss experience an additional drop in hearing ability suddeenly or over time. Others develop a hearing loss which gradually worsens (progressive hearing loss.) It is important for children and adults to make regular visits with their audiologist to monitor their hearing over time.