A sound is a vibration in the air, like a ripple in a pond. Sounds create sound waves. Your ears take in these sound waves and then send messages about them to your brain.
There are three major parts of the ear that work together to collect sounds and send them to the brain: the outer ear, the middle ear, and the inner ear. The outer ear directs sound to the middle ear, which then transmits the sound waves from the eardrum to the inner ear. The inner ear converts sound waves into nerve signals which the brain interprets. All of this happens in a fraction of a second!
OUTER EAR
The outer ear has three sections: the pinna, ear canal, and the outer layer of the eardrum. The pinna is the part of the ear on the outside of our heads. It acts as a kind of funnel, directing sound waves further into the ear. The ear canal is a tube that helps sound waves travel from the pinna to the eardrum.
MIDDLE EAR
The middle ear consists of the rest of the eardrum and three tiny bones called the hammer, or malleus (MAL-ee-us); the anvil, or incus (IN-kus); and the stirrup, or stapes (STAY-peez). The eardrum is a thin sheet of tissue that vibrates when the sound waves hit it. These vibrations are transmitted to these middle ear bones, which in turn pass signals on to the inner ear.
INNER EAR
The inner ear contains a snail-shaped, fluid-filled organ called the cochlea (KO-klee-uh). Every second, the cochlea receives thousands of vibrations as ripples in its fluid. The cochlea has a complex structure called the organ of Corti, which is filled with special hair cells. When the stapes vibrates, pressure waves are pushed into the cochlea. As the hair cells move back and forth, nerve impulses are triggered that send signals to the hearing center of the brain. The brain then translates the signals into sounds that we recognize and understand.
How Hearing Aids Work
Hearing loss is a common problem caused by overexposure to loud noise, aging, disease, and/or heredity. Depending on the type of hearing loss a person has, a hearing aid can improve his hearing in both quiet and noisy surroundings.
What Is a Hearing Aid?
A hearing aid is a small electronic device that is worn in or behind the ear. It makes some sounds louder so that a person with hearing loss can listen, communicate, and participate more fully in daily activities.
A hearing aid has three basic parts: a microphone, amplifier, and speaker. The hearing aid receives sound through a microphone, which converts the sound waves to electrical signals and sends them to an amplifier. The amplifier makes the sound louder and sends the amplified sound to the ear through the speaker.
How Hearing Aids Help
Hearing aids are very useful in improving the hearing and speech comprehension of people who have hearing loss due to damage of the small sensory cells in the inner ear (called hair cells). This type of hearing loss is called sensorineural hearing loss.
As mentioned before, the inner ear is made up of a snail-shaped chamber called the cochlea, which is filled with fluid and lined with thousands of tiny hair cells (an outer row and an inner row). When sound vibrations move through this fluid, the tiny outer hair cells react first by amplifying sounds. Then the inner hair cells translate the vibrations into electrical nerve impulses and send them to the auditory nerve, which connects the inner ear to the brain.
Hearing aids intensify sound vibrations that the damaged outer hair cells have trouble amplifying. The more a person’s outer hair cells are damaged, the higher the hearing aid is turned on.
Listening to loud sounds can harm your hearing.
This is true. Loud sounds can physically damage the hair cells in your cochlea. Sometimes this is temporary, like when you have “ringing in your ears” that lasts for a few hours after you’ve gone to an event with loud music. But over time, too much loud noise can cause permanent hearing loss.