How Do We Hear?

Hearing  depends on a series of complex steps that change sound waves into  electrical signals. Then, our auditory nerve carries these signals to  the brain. The ear is made up of three parts:

• the outer ear, which includes the pinna, and the ear canal all the way up to the eardrum.
• the middle ear, which includes the eardrum, and the bones of the middle ear.
• the inner ear, which includes the cochlea, a snail-shaped structure filled with fluid.

In order for us to hear, all three parts of our ear must be working together and functioning correctly.

1. Sound waves enter the outer ear and travel through the ear canal, which leads to the eardrum.
2. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. 
3. The bones in the middle ear amplify or increase the sound vibrations and send them to the cochlea. 
4. The vibrations cause the fluid inside the cochlea to ripple, which causes tiny little hairs in the fluid to move too. 

    5.  As the hair cells move up and down, they create electrical impulses. 

The auditory nerve carries this electrical signal to the brain, which turns it into a sound that we recognize and understand.

If  any parts of your ear are not functioning properly, or the part of your  brain that processes sound is not working properly, sounds become  distorted. This is why you experience hearing loss.

There are three types of hearing loss depends on what part of  the ear is damaged. These are:

1.  Sensorineural hearing loss

2.  Conductive hearing loss

3.  Mixed hearing loss

Sensorineural hearing loss is the most common type of hearing loss which happens when there is damage in the inner ear or nerve pathway to the brain. It impacts the pathways from your inner ear to your brain. Soft sounds may be hard to hear. Even louder sounds may be unclear or may sound muffled. Most  of the time, sensorineural hearing loss cannot be corrected medically  or surgically. Hearing aids may help you to hear, and audiologists can help if you have this type of hearing loss.

Conductive hearing loss is typically the result of obstructions in the  outer or middle ear prevents sound from getting to the inner ear. It may be hard to hear soft sounds, and louder sounds may by muffled.  Conductive hearing loss can often be fixed surgically or with medication.

Mixed hearing loss is a combination of sensorineural and conductive hearing loss. This  means that there is possible damage in the outer or middle ear, and in the  inner ear or nerve pathway to the brain. Anything that causes a  conductive hearing loss or sensorineural hearing loss can lead to a mixed hearing loss. 

Not all hearing loss is the same and treatment will depend on how serious your hearing loss is. 

A consultation with a hearing professional can help determine the type, cause and degree of your hearing loss. 

The  degree of hearing loss is based on how loud sounds need to be for you to be able to hear them. There are four clinically labelled degrees of hearing  loss:

You may hear some speech sounds but will have difficulty with soft sounds.

You’ll struggle to hear or understand speech when someone is talking at a normal level.

You may only hear some loud sounds with little-to-no speech when someone is talking at a normal level. 

You may only hear very loud sounds and no speech at all.