How Do We Hear?
HOW DOES OUR HEARING WORK?
How Do We Hear Sound?
Did you know that we can hear even before we are born? Yes, babies can hear inside the womb, and when we are born our ears and hearing is fully developed!
Our ears have two parts and outer ear and the inner ear. Our ears pick up all the sounds around us and then translate this information via vibration or waves into a form our brain can understand. One of the most remarkable things about this process is that it is completely automatic. Your sense of smell, taste and vision all involve chemical reactions, but your hearing system is based solely on vibrations and physical movement.
The pinna, the outer part of the ear, serves to "catch" the sound waves. This is your outer ear, and is pointed forward and it has got a number of curves. If a sound is coming from behind you or above you, it’ll rebound off the pinna in another way than if it is coming from out front of you or below you. It is positioned between the ear canal and the middle ear.
The middle ear is hooked up to the throat thru the Eustachian tube. Since air from the atmosphere flows in from your outer ear and your mouth, the air pressure on both sides of the eardrum remains equal. This keeps the complete surface taut so it’ll vibrate no matter what part of it actually is hit by a sound wave. This little flap of skin acts like the diaphragm in a microphone. Higher-pitch sound waves move the drum more rapidly, and louder sound moves the drum a greater distance.
This is the job of the ossicles, a group of tiny bones in the middle ear. The ossicles are actually the smallest bones in your body. They include:
- Malleus, generally refer to as the hammer
- Incus, generally refer to as the anvil
- Stapes, generally refer to as the stirrup
The cochlea in the inner ear conducts sound thru a liquid, rather than thru air.
The tiny force felt at the eardrum isn’t powerful enough to move this liquid. Before the sound passes on to the inner ear, the total pressure (force per unit of area) must be amplified. This is the job of the ossicles, a grouping of miniscule bones in the middle ear. The ossicles are essentially the littlest bones in your body.
The malleus is attached to the middle of the eardrum, on the inner side.
When the eardrum vibrates, it moves the malleus from side to side like a lever. The other end of the malleus is attached to the incus, which is attached to the stapes. The other end of the stapes — its faceplate — rests against the cochlea, thru the oval window.
The ossicles amplify the force from the eardrum in 2 ways.
The main amplification comes from the size difference between the eardrum and the stirrup. Sound waves apply force to every square inch of the eardrum, and the eardrum transfers all this energy to the stapes.
The malleus is lengthier compared to the size of the incus, thus forming a basic lever between the eardrum and the stapes. The malleus moves a larger distance, and the incus moves with larger force. The pressure applied to the cochlear liquid is about twenty-two times the pressure felt at the eardrum.
The cochlea is by a large margin the most complicated part of the ear. The cochlea structure contains three diagonally opposite tubes separated from one another by sensitive surfaces. It is also clearer if we treat a couple of the tubes, the scala vestibuli and the scala media, as one chamber. The surface between these tubes is so thin that sound waves travel as if the tubes weren’t separated at all.
The stapes moves backwards and forwards, making pressure waves in the complete cochlea. The round window surface separating the cochlea from the middle ear gives the liquid somewhere to go. It moves out when the stapes pushes in and moves in when the stapes pulls out.
The middle surface, the basilar surface, is a firm surface that extends across the length of the cochlea. This force starts a wave moving along the outside of the surface. The wave travels something similar to ripples along the outside of a pool, moving from the oval window down to the other end of the cochlea.
The basilar surface has a bizarre structure.
It’s made from twenty thousand to thirty thousand reed-like fibers that extend across the width of the cochlea. Close to the oval window, the fibers are short and stiff. As you move toward the other end of the tubes, the fibers get longer and more limber. This gives the fibers different resonant frequencies. As the wave moves along the majority of the surface, it can’t release much energy — the surface is too tense. In the subsequent section, we’ll look at how small hairs help us hear sound.
The higher pitches vibrate the basilar surface most intensely close to the oval window, and lower pitches vibrate the basilar surface most intensely at the crossroads further down the cochlea. But how will the brain know where these vibrations occur?
The organ of corti is a structure containing thousands of little hair cells. It lies on the outside of the basilar surface and extends across the length of the cochlea.
Until a wave reaches the fibers with a resonant frequency, it does not move the basilar surface a great deal; however the movement is strong enough to move the organ of corti hair cells at that point. Now the brain knows a sound is louder because more hair cells are turned on in an area.
The cochlea snail shelled shape only sends raw information — complicated patterns of electric impulses. The brain is sort of similar to your home computer, as it is taking this inputted information and making some sense of it all.
For the most part doctors and researchers are still confused by some of the inner workings of the connection between the brain and the ear, but with modern technology and imaging of the brain, it is all starting to look and sound a lot more clearer.
Protecting our hearing is very important; because for the most part once your hearing is impaired it cannot be repaired. Hearing aids maybe your only option at that point.
How do you lose your hearing? Follow this link to read about
Sudden Hearing Loss Causes And Symptoms Treatments
Treatment For Sudden Hearing Loss
Sudden Hearing Loss Caused by Work Environment
Have your hearing checked, and buy hearing protection for the work place.
How the inner ear works.
Do You Hear What We Hear? Wikipedia
Normal Ear Anatomy & Hearing
How does are hearing work?Sound entering the ear canal causes the ear-drum to vibrat
Mail this post
Tags: How does hearing work, Sudden hearing loss causes and symptoms treatments, Treatment for sudden hearing loss
May 19th, 2010 at 1:59 am
Spectacular posting, I share the same views. I wonder why this world does indeed not feel just like myself and also the blog site possessor
May 19th, 2010 at 2:11 am
Extraordinary write-up bro. This important is just a totally nicely structured piece of writing, just the information I was hunting to find. I am truly thankful