Types of Hearing Loss
There are different types of hearing loss dependent on which part of the hearing pathway is affected. Drs. Jessee and Streich will try to localize where the problem is, which allows her to classify the type of hearing loss. The classification is important in determining the appropriate treatment.
Do You Have Hearing Loss?
If these symptoms sound familiar, you may have hearing loss:
If you notice one or more of these symptoms, call our office to make an appointment for a complete audiological evaluation (hearing test).
Conductive Hearing Loss
This type of hearing loss is due to any condition that interferes with the transmission of sound through the outer and middle ear to the inner ear. This type of hearing loss is often medically treatable. The interference in sound transmission is usually due to a problem in the:
- External ear canal (such as earwax or debris)
- Mobility of the eardrum (such as fluid or otitis media)
- Three bones in the middle ear (such as otosclerosis)
- Middle ear cavity
- Eustachian tube
Medicine can improve problems with the outer or middle ear in a majority of cases, and when it can’t, hearing aids are very successful.
Sensorineural Hearing Loss
Hearing aids are most commonly fit on people with sensorineural hearing loss. This type of hearing loss is often referred to as ‘nerve deafness,’ as the damage occurs in the inner ear. The cochlea has approximately 30,000 hair cells. The hair cells in the large end of the cochlea respond to very high pitched sounds and those in the small end (and throughout much of the rest of the cochlea) respond to low pitched sounds. These hair cells and the nerve that connects them to the brain are susceptible to damage from a variety of causes. These are just a few of the causes:
- Presbycusis (hearing loss due to aging)
- Noise exposure
- Ototoxicity (medications that damage the cochlea)
The term “sensory” hearing loss is applied when the damage is in the inner ear. “Neural” hearing loss is the correct term to use when the damage is in the acoustic nerve, anywhere between its fibers at the base of the hair cells and the relay stations in the brain (the auditory nuclei).
Central Hearing Loss
In central hearing loss, the problem lies in the central nervous system, at some point within the brain. Interpreting speech is a complex task. Some people with normal hearing have trouble understanding what is being said. Central auditory processing disorder frequently leads people to think they have hearing loss when their hearing is actually normal. The problem involves a person’s inability to filter out competing auditory signals. Hearing aids are rarely used for the treatment of central hearing loss.
Mixed Hearing Loss
When a person experiences two or more types of hearing impairment, this is called a mixed hearing loss. This term is used when both conductive and sensorineural hearing losses are present on the same ear. Often medical treatment will be sought for the conductive component and hearing aids used for the sensorineural component.