How do we hear sounds?
Hearing is a complex process through which sound waves are transformed into electrical signals that are carried to the brain and allow us to determine the sounds we are hearing. The process involves a series of complex steps, as follows:
- Sound waves in the air enter the outer ear and travel to the eardrum through a narrow passageway known as the ear canal.
- When the sound waves reach the eardrum, they cause it to vibrate, and these vibrations are sent to three tiny bones that are found in the middle ear. These bones are known as incus, malleus, and stapes.
- The three bones in the middle are responsible for amplifying and increasing the sound vibrations and sending them to the cochlea. The cochlea is a snail-shaped structure, full of fluid, and located in the inner ear. An elastic partition separates the upper and the lower part of the cochlea; the partition is known as the basilar membrane.
- The vibrations sent to the cochlea cause the fluid inside of it to ripple and send waveforms along the basilar membrane. Hair cells, also known as sensory cells positioned on top of the basilar membrane, ride this wave. Depending on the positioning of the hair cells along the cochlea, you can detect higher- or lower-pitched sounds.
- As these hair cells continue to ride the wave, microscopic projections, known as stereocilia, which sit atop the hair cells, bump against an overlying structure. As they bump into the structure, they begin to bend, which causes channels at the tips of the stereocilia to open up. When these channels are opened, chemicals rush into the cells, creating an electrical signal.
- The electrical signal is carried to the brain via the auditory nerve and allows us to recognize and understand the sounds we are hearing.
Types of Hearing Loss
Hearing loss is usually a gradual process that commonly occurs as you age. It can also be caused by chronic exposure to loud noises. Most types of hearing loss cannot be reversed, but with the right help, you can improve what you can hear. Hearing loss can be categorized as one of three types, including:
Sensorineural hearing loss
Sensorineural is the most common type of hearing loss, which is caused by problems in the inner ear, sensory organs, or the vestibulocochlear nerve. Sensorineural hearing loss can be caused by loud noise exposure, genetics, medications, head trauma and aging also called presbycusis hearing loss.
Conductive Hearing loss
This hearing loss occurs when sound waves encounter a problem travelling anywhere along the pathway through the outer ear, the eardrum, or the middle ear.
Mixed Hearing Loss (a combination of conductive and sensorineural)
Mixed hearing loss is a combination of conductive and sensorineural hearing loss and can be caused by a problem in the outer or middle ear or an auditory nerve. Mixed hearing loss can occur following an injury to the head, a long-term infection, or if an individual has a greater likelihood due to family history.
How is hearing loss treated?
If you are suffering from hearing loss, there are ways to help restore your hearing. The type of treatment is dependent on the cause as well as the severity of the hearing loss. Options for treatment include:
Removing wax blockage
When you have an excessive amount of earwax, it can cause a blockage to occur, ultimately causing hearing loss. However, it can easily be reversed if the earwax is removed. This is usually done using suction, flushing with water or using special instruments.
If you are experiencing hearing loss, a hearing aid can be helpful. At Hear Clear Canada, we can provide you with the perfect hearing aid, ensuring comfort and a great fit. 95% of Canadians with hearing loss can be treated with hearing aids. Hearing aids cannot cure hearing loss but can drastically improve your hearing and ability to communicate with others.
If you have abnormalities in your eardrum or the bones in your ear associated with hearing, they may be treated using surgery. Additionally, if you are prone to repeated infections that cause fluid build up in your ears, you can have small tubes surgically inserted in your ears to help drain the fluid.
If your hearing loss has become profound and cannot be treated from conventional hearing aids, a cochlear implant may be recommended. A cochlear implant works by bypassing all of the damaged and nonfunctional parts of the inner ear and causes direct stimulation of the auditory nerve. This is unlike a hearing aid that amplifies sound and directs it into your ear canal. Your hearing healthcare provider will let you know if you are a candidate for a cochlear implant.