Understanding How the Ear Works

The anatomy of the ear may be complex, but not all that complicated when you look at it in simple terms. Only a couple of anatomical parts assist in hearing. Nevertheless, if something goes awry with one of these parts, hearing can be impacted.

The three parts of the ear

Basically, the ear is comprised of three parts – the outer ear, the middle ear and the inner ear. Each of the part is responsible for a specific function in the detection and interpretation of sound.

The outer ear

The outer ear is the first part of the ear that is involved in the hearing process. The pinna or ear flap is the name of the part that can be seen on the sides of the head. This is the section of the ear’s anatomy that collects vibrations and safeguards the eardrum in the middle ear from damage.

Where the transmission of sound begins

The external auditory canal is located just inside the pinna, also a part of the outer ear. Sound first travels through the external auditory canal. The outer ear and middle ear are segregated by the eardrum, which is also known scientifically as the tympanic membrane. Moreover, the eardrum is situated at the end of the external auditory canal. Therefore, sound first goes through the external auditory canal, located in the outer part of the ear (inside the pinna) before it reaches the eardrum in the middle ear.

The middle ear

The middle ear is an air-filled cavity that is made up of the three smallest bones in the body. These very tiny bones are called ossicles. The bones are known individually as the malleus (also called the hammer), the incus (known as the anvil) and the stapes (known in layman’s terms as the stirrup). Therefore, the ossicles in the middle ear are commonly referred to as the hammer, anvil and stirrup.

These tiny bones span across the middle ear. While the hammer or malleus is affixed to the eardrum, the stapes or stirrup is attached to the oval window – the section of the ear that divides the middle and 3rd part of the ear anatomy known as the inner ear.

The inner ear

The inner ear is made of two organs that perform two different functions. The semicircular canals in the inner ear are chambers that contain fluid and do not have any direct impact on hearing. Instead, these canals operate to maintain the equilibrium or balance of the body. Therefore, the canals in the inner ear serve to keep you from appearing disoriented when you perform everyday activities.

The role of the cochlea

The cochlea is the second organ in the inner ear. The cochlea, which resembles a snail’s shell, is separated into three fluid-filled chambers. The cochlea serves as the microphone for hearing. The central chamber of the cochlea is known as the organ of corti. This small organ contains approximately 20,000 nerves cells, each resembling very tiny hairs that are affixed to it. These microscopic “hairs” are linked to the part known as the auditory nerve, which transmits signals to the brain for hearing.

How the transmission of sound works

Now that you have an idea about the way the ear is designed, you can better understand how sound is transmitted. Sound can be defined as any noise, including rain, music, or speech, that sends sound waves or vibrations into the air. When these sound waves are made, the pinna collects the vibrations. The vibrations then make their way through the external auditory canal. Through this passage, the waves strike the eardrum, which, in turn, transmits the vibrations at the same precise frequency they were originally collected in the pinna.

The vibrations then make a passage through the ossicles of the ear, known, again, as the malleus (hammer), incus (anvil) and stapes (stirrup). The vibrations travel to the oval window, through the fluid of the cochlea and, finally, to the very tiny nerve cells in the central chamber of the cochlea. By the time the vibrations reach the nerve cells, they trigger the very tiny hair-like cells to produce an electrical impulse – with each vibration traveling along the auditory nerve and onto the brain. The brain, in turn, interprets the impulses as sound.

How hearing loss typically occurs

When sound is excessive, any of the delicate parts of the ear can be damaged. That is how, over time, hearing loss can occur. Thus, the gradual exposure to loud noise without hearing protection can cause one to lose his or her hearing after a while.