Learn more about hearing, from how sound is received in our ears and how hearing works in the brain in our complete guide to explain how hearing works.
You might be wondering how we hear sounds. Hearing is the process of sound travelling through the outer, middle and inner ear to be interpreted by the brain. There are four main steps of hearing:
The ear can be divided into three main parts, each part playing an important role in transmitting sound. The three main parts of your ear are the outer, middle, and inner ear.
Your hearing depends on all three parts working together as a team and if you have a problem anywhere in the process, you may experience hearing loss.
The outer ear consists of the auricle (pinna), ear canal, and eardrum. The pinna is the part of the ear that you see on the side of your head. Its main job is to collect sound waves, which are vibrations, and funnel them into your ear canal, where the sound is amplified. The glands in the skin lining the ear canal produce earwax which protects the canal by cleaning out dirt and helps prevent infections. The sound waves travel through the ear canal and strike the eardrum causing it to move or vibrate.
The middle ear is separated from the outer ear by the eardrum, which is a thin piece of tissue that stretches across the ear canal. As sound waves strike the eardrum causing it to move, the movement leads to the vibration of very small bones called ossicles. The ossicles are:
The vibrations of the ossicles creates movement of the fluid in the inner ear, or cochlea. The movement of the fluid causes the hair cells to move and sends an electrical nerve impulse from the inner ear to the auditory nerve and up to the brain.
The inner ear also contains the vestibular organ that is responsible for balance.
Our ears work as a team to help improve our ability to locate sound and distribute volume. Being able to hear with both ears makes it easier to understand speech and tell where sounds are coming from. Some people may experience hearing loss in one ear, but not the other.
The cochlea is a part of the inner ear and it contains hair cells which convert the liquid motion into electrical nerve impulses that travel to the brain.
At birth, each ear normally has about 12,000 hair cells that sit on a membrane that vibrates in response to sound. Each hair cell sits on a different part of the membrane and therefore responds to different frequencies. The hair cells are responsible for converting the mechanical vibrations into electrical signals, which are passed onto the auditory nerve.
The auditory nerve connects the cochlea to the auditory cortex in the brain. The electrical signals from the hair cells excite the nerve fibers which carry information about a different frequency to the brain. The information is analyzed by multiple brain centers as it flows to the auditory cortex.
When we hear sound waves enter the ear canal and move toward the eardrum which causes the eardrum to vibrate making three tiny bones located in the middle ear to move. The hair cells within the cochlea catch the vibrations and turn them into electrical signals that are carried to the auditory nerve in the brain where it interprets the signals as sound. If there is a problem along the pathway it can cause you to have hearing loss.
If you think you or a loved one are showing signs of hearing loss, you can start by taking a complimentary online hearing test. You just need an internet connection and a pair of headphones, and you can do it from the comfort of your own home. Our online hearing test takes a few minutes, and you can have the results emailed to you. It will tell you if you are showing signs of hearing loss.