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How Ears Work

Find out how ears work in our no nonsense guide. Ears are complicated things, but their explanation doesn’t have to be. 

how-do-ears-work

We know how important our sense of hearing is. Just imagine how life would be like if you could not hear beautiful sounds like babies laughing, birds chirping, and music playing. Our ears are indeed one of the most complicated organs in our body, and today we’ll dig a bit deeper into how they work.

Whenever someone or something makes a sound, a vibration or sound wave is sent in all directions. Of course, these vibrations are invisible, but our ears capture them. They are perfectly designed to “collect” sound waves, much like a satellite dish. The shape of our ears are perfectly designed to funnel sound into the ear canal. They even amplify frequencies of sound around the vocal range.

When our ears capture sound waves, they are then fed through the ear canal and subject to various processes before reaching the brain in a quite different from.

In order to better understand how we hear and how our ears work, let’s talk about all the details concerning them.

Anatomy of the Ear

The human ear is made up of three main parts: the outer ear, which is also called the pinna, the middle ear, and then the inner ear. All these three need to work together in order to detect sound waves and vibration. So, how do ears work?

The Outer Earear

The outer ear includes the auricle or the cartilage covered by skin and placed on opposite sides of the head; the auditory canal which is also called the ear canal; and the eardrum outer layer which is also called the tympanic membrane. Basically, this part of the ear is the one visible to people. It is what we pierce to wear earrings and where your friends whisper to share secrets.

The ear canal is where ear wax is produced. It may  be perceived as gunky and dirty but the ear wax plays an important role. It protects the canal because it contains chemicals that can fight off infections inside the ear canal. It is also responsible for collecting dirt so it is not a worthless type of gunk, in fact it is very useful.

The function of the outer ear is to collect sounds. The sounds travel through the auricle and the auditory canal which is a short tube that ends at the eardrum.

The Middle Ear

middle-ear

The middle ear includes the eardrum; the cavity which is also called the tympanic cavity; and the ossicles which are three tiny bones that are attached. These tiny bones are called the malleus or hammer, the incus or anvil, and the stapes or stirrup.

The malleus is a long handle which is attached to the eardrum. The incus is the bridge bone between the malleus and the stapes. The stapes is the footplate which is also the smallest bone in the body.

When the sound enters through the outer ear, it travels through the middle ear which causes the eardrum and the ossicles to vibrate. It becomes louder as it travels and changes its form from air to liquid.

The Inner Ear

inner-ear

The inner ear includes the oval window, the semicircular ducts, the cochlea, and the auditory tube.

The oval window connects the middle ear to the inner ear while the semicircular ducts are filled with fluid and are attached to the cochlea and nerves. They send information to the brain on balance and head position.

The cochlea is an organ of hearing, which is spiral in shape. It transforms sound into signals that are then sent to the brain. The auditory tube drains the fluid from the middle ear into the throat behind the nose.

The cochlea plays a vital role as it takes the fluid vibration of sounds from the semicircular ducts that surround it and then translates these vibrations into signals that are sent to the brain. The nerves that are responsible for this are the vestibular nerve and cochlear nerve.

How We Hear

The process of hearing precious sounds begins with the outer ear. Whenever a sound is made, the sound waves travel down the external auditory canal and strike the tympanic membrane or more commonly known as the eardrum.

The eardrum then vibrates and these vibrations are passed on to the three tiny bones in the middle ear called the ossicles. What happens next is that the ossicles amplify the sound and send them to the inner ear and into the cochlea which is the fluid-filled hearing organ.

When the sound waves reach the inner ear, the vibrations are converted into electrical impulses. These impulses are then sent by the auditory nerve to the brain. The brain then translates the electrical impulses into the sound that we know and understand.

What Happens When We Have Hearing Problems?

As mentioned earlier, all parts of the ear need to work together in order for us to hear a sound. Normally, the different parts of the ear pass information to the brain which translates the sound. If a part of the ear is not functioning or responding well, you will have a hearing problem.

If the problem happens in the outer ear or the middle ear, it can lead to inefficient transfer of sounds. The cochlea may still be working, but the sound is not being conducted or transferred enough. This type of problem or hearing loss is called conducive hearing loss. It can be caused by an ear infection, a hole in the eardrum, or otosclerosis. Otosclerosis is an abnormal growth of bone, which is like a sponge in the middle ear.

If the problem is in the inner ear, it means that the cochlea was able to receive the sound but it is not fully passed on to the hearing nerve. There is also a possibility that the hearing nerve is not passing on information very well or fails to pass it at all. This is called a sensorineural hearing loss which can be caused by loud noise, old age, or certain types of diseases.

We should take special precautions to protect our ears, as they are very sensitive. Soundproofing is a also a great way to limit our exposure to excessive noise.

That was a pretty brief run through of how ears work, but it gives a good overview of just what happens. If you have any questions then please get in contact and we’ll do our best to help. Check back soon as there’s lots more coming at Home Recording Pro over the next few months.

Image Sources  

By Henry Vandyke Carter – Henry Gray (1918) Anatomy of the Human Body. Bartleby.com: Gray’s Anatomy, Plate 904, Public Domain, https://commons.wikimedia.org/w/index.php?curid=566846

Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=29025011

Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=29025010

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