Types of Hearing Loss

Did you know there are three different types of hearing loss? Depending on where the problem occurs in the hearing system, hearing loss will be classified as a specific type. Let’s first learn a little about how humans hear and the different parts of our hearing system. There are three main parts to the human ear – outer, middle, and inner.

1. The outer ear includes the pinna and the ear canal. The pinna, the visible part of the ear on the side of your head, collects sound waves and directs them down the ear canal to the eardrum.
2. The middle ear transfers sound waves from the eardrum to the ossicles. The ossicles are the three smallest bones in the human body. The last ossicle is attached to the hearing organ called the cochlea, which is in the inner ear.
3. The inner ear is comprised of the cochlea (hearing organ), the vestibular system (balance organs), and the hearing nerve (cranial nerve VIII). The sensory cells inside the cochlea electrically stimulate the hearing nerve. The hearing nerve takes the sound signal to the brain where it is interpreted.

Now that you know a little bit about how the hearing system works and the different parts of the hearing system, let’s learn about the three types of hearing loss.

1. A conductive hearing loss occurs when there is a problem with how sound transfers through the outer or middle ear. This type of hearing loss typically only involves reduction in volume of sound. Many causes of a conductive hearing loss can be medically or surgically treated, although there are causes that are permanent.  Causes of a conductive hearing loss include: middle ear infections, otosclerosis, perforation of the eardrum, and occluding earwax.
2. A sensorineural hearing loss occurs when there is a problem with the inner ear. Sensorineural hearing loss is the most common type of hearing loss. This type of hearing loss not only involves the reduction in volume of sound, but also reduces the ability to clearly hear sound. Generally, this type of hearing loss cannot be medically corrected. Options for managing a sensorineural hearing loss include the use of hearing aids or cochlear implants. Common causes of sensorineural hearing loss include: loud noise exposure, presbycusis (age related hearing loss), ototoxic medications, smoking, cardiovascular problems, diabetes, and genetics.
3. A mixed hearing loss occurs when a person has both a conductive and a sensorineural hearing loss at the same time.

If you experience difficulty hearing or understanding speech, make sure to have your hearing tested by an Audiologist. An Audiologist will be able to assess the different parts of your hearing system to determine where the problem is occurring and what may be causing it. Including a hearing test with an Audiologist in your annual healthcare routine is also of benefit to be able to assess any changes in your hearing that may be difficult to detect at first.