Anatomy of Your Hearing
- Outer Ear
- Ear Canal
- 3 Ossicles- Malleus, Incus, Stapes
- Oval Window
- Eustachian Tube
- Auditory Nerve
- Back Portion of Your Brain that Deals with Sound
How Your Hearing Works
- Sound waves transmit through the air from their various sound sources. The outer ear, or pinna, collects the oncoming sound waves and channels them into the ear canal. The outer ear gives you excellent acoustics to enhance certain desirable frequencies while filtering out more undesirable frequencies.
- The sound waves vibrate the eardrum, setting the three tiny bones in the middle ear into a chain reaction.
- As the last of the three bones, the stapes, is triggered, it taps the oval window on the outside of the cochlea and causes a hydraulic effect in the cochlea. This disrupts the fluid forcing it move through the cilia or 35,000-45,000 hair like nerve endings in the cochlea.
- The fluid forces the hair like cilia to bend down which creates electrical impulses which then pass up the auditory nerve to the brain.
- As these impulses reach the brain, (the left ear transfers impulses to the back portion of the right brain, the right ear transfers impulses to the back portion of the left brain giving you spatial orientation, which helps in overall sense of what’s going on around and the sense of wholeness in your connection to your surroundings- Very Important) the brain then recognizes the types of sound they are i.e. speech, birds, cars, etc. Also very important to keep your brain properly stimulated with sound to strengthen memory, focus, retain grey matter, help prevent Alzheimer’s, dementia and many other mental issues. See the related article from Johns Hopkins University
The Outer Ear
The outer ear or pinna is a very effective acoustic design to help enhance the sounds you want to hear while naturally filtering out the less desirable ambient sounds. It collects the sounds and channels them into your ear canal and on towards the eardrum.
The ear canal is very important to understand. The ear canal is the most sensitive part of your external body. It has very few, thin layers of skin inside. It is highly vascularized, meaning it has a lot of blood flow. It also has very fine hairs inside (these are not the hairs that deal with sound as some people get confused), these deal with producing ear wax and helping move it out of the ear naturally. The delicate nature of the ear canal makes it very important to care for it the right way. See more on how to take care of your ear canal properly.
The Middle Ear
The eardrum, or tympanic membrane (TM), separates the outer ear from the middle ear. The eardrum is both very durable and flexible. Always keep things out of your ear and away from your eardrum, because while it is durable for normal situations, it can be easily punctured or damaged if you’re not careful. If you have any pain or infection in your ear canal take care of it immediately with your physician, so worse problems don’t develop.
Beyond the eardrum are three tiny ossicles or bones. These three bones are called the malleus, incus and stapes otherwise known as the hammer, anvil and stirrup. As the eardrum vibrates, it sets these bones into action causing a mechanical chain reaction. The stapes is the last in line and the one to tap the oval window, which starts the workings in the inner ear.
The Eustachian tube allows your middle ear to equalize it’s pressure, which helps your head feel much better. We’ve all experienced the pressure of rising in altitude until your ears “pop”. This pressure takes place until your Eustachian Tube can normalize the inner air pressure enough to restore your ears back to normal. As most people know, plugging your nose and blowing gently into your ears will often help equalize this immediately. The Eustachian Tube can be involuntarily opened by swallowing, yawning, or chewing. Drinking plenty of water also helps the Eustachian Tube function more properly. Your hearing will also be temporarily diminished when you get a common cold and mucous builds up in the Eustachian Tube and Middle Ear. Drinking lots of water to flush this out will help. If the problem persists, see your physician and basic antibiotics can help restore this to normal.
The Inner Ear
The inner ear is your hearing organ and is well-protected inside the temporal bone inside your skull.
The inner ear has two main parts: the semicircular canals and the cochlea.
- Semicircular canals – These contain tiny crystals at the top of them that coordinate your overall balance. These have nothing to do with you hearing.
- Cochlea – The cochlea is a snail-like looking hearing organ, which is a filled with fluid. Inside the cochlea are 35,000-45,000 thin hair-like nerve endings. These act like strings on a piano. When the fluid and the various frequencies in various intensities brush past these nerve endings, they bend down causing an electrical impulse, which then transmits through the auditory nerve and up to the brain. Each nerve ending produces a different tone like strings on a piano or guitar. The guitar has 6-12 strings. The piano has 88 strings. Both can create great music from those limited numbers of strings. Now imagine an instrument that has 35,000-45,000 strings PER EAR, which connect in the brain for the ultimate sound experience. This is the most advanced sound system known to man, but unfortunately gets damaged or worn out over time. Taking care of your hearing, even if that means getting hearing aids, will pay great dividends throughout your life by having the tremendous gift of hearing in your life.