LifeSound Hearing

Anatomy of the Ear

How do we hear?

Hearing can be explained utilizing the structural anatomy and function of each part.  The following will explain how vibrations in the air are turned into the miracle of sound. 

The outer ear

The outer ear is the part of the ear that we can see from the outside.  It is structurally comprised of the pinna, the ear canal and the ear drum.  The primary function is to gather sound waves from the environment and concentrate them towards the middle ear. 

Outer Ear

Also known as the auricle, the pinna is the skin covered cartilage portion of the ear.  It is known as the part of the ear that you can see.  The pinna is specially shaped to capture sound waves and direct them towards the ear drum or tympanic membrane. 

Also known as the external auditory meatus, the ear canal is a pathway that connects the pinna to the ear drum.  The primary function is to deliver sound waves to the ear drum.  This canal also contains the glands that produce cerumen, also know as ear wax.  Ear wax helps to protect the ear canal while keeping it clean and lubricated.

Also known as the tympanic membrane, the ear drum is a thin membrane that receives sounds waves and transmits them to the middle ear in the form of vibrations. 

The middle ear?

The middle ear contains three bones known as the ossicles.  These tiny bones transfer vibrations from the ear drum into the inner ear in the form of compression or longitudinal waves.  These bones are commonly referred to as the hammer, anvil and stirrup.

Middle Ear

The malleus, or hammer bone, is the closest to the outer ear. It is attached to the inner surface of the ear drum and connects to the incus or anvil

The incus, or anvil bone connects the malleus and the stapes.  It is responsible for transmitting vibrations between to the other ossicles.

The smallest and lightest bone in the human body, the stapes, or stirrup bone, is the final of the three ossicles. It bridges the incus to the oval window, and it transfers sound vibration to the inner ear. 

The Eustachian tube is a tube that links the middle ear to the pharynx.  It is utilized to normalize pressure in the middle ear and allows mucus to drain out of the middle ear.  

The inner ear

The inner ear contains the oval window, the cochlea, the semicircular canals and a portion of the auditory nerve. The inner ear also contains the vestibular system which plays a role in maintaining balance.

Inner Ear

The oval window is a membrane that connects the inner ear to the middle ear.  The waves from the stapes bone travels through the oval window and into the cochlea. 

The cochlea is a spiral-shaped, fluid-filled cavity containing the organ of corti and the hair cells.  Both are crucial in transforming waves from the middle ear into electrochemical impulses for the brain. 

The semicircular canals are three fluid-filled tubes in the inner ear responsible for balance. The movement of fluid through the canals sends nerve impulses to the brain which helps an individual maintain their position in space.

The auditory nerve is responsible for carrying neural impulses from the cochlea to the brain for interpretation. 

Sound is created using all of these complex anatomical structures.  A problem with any of the structures of the ear can have consequences on the whole process of hearing. If you or a loved one are experiencing problems hearing, make an appointment to visit a LifeSound Hearing specialist today. 

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