The Functions of the Human Ear

You might live decades and not think much about the functions of your ears. On the other hand, some people are plagued with ear problems throughout their lives. The reason for such contrast has something to do with how delicate and intricate human ear function is. Ear function is susceptible to several problems from the outside. When healthy, ears provide you with two essential senses--a sense of hearing and a sense of balance.

Hearing

• Sound waves traveling through the air are funneled into your ear canals by your earlobes. Sound waves entering your ear canals hit each of your eardrums, and they begin to pulse and vibrate. A tiny bone called the malleus is connected to the backside of each eardrum. The malleus connects to two other bones, the incus and stapes, and these bones form an ossicular chain inside your middle ear. Sound waves are mechanically transferred through the ossicular chain, vibrating the oval window--a membrane leading to your inner ear.

  On the other side of the oval window is your cochlea. The cochlea is a spiraled bony structure filled with fluid and nerve endings. Sound waves vibrate the nerves throughout the cochlea, causing an electrical impulse that is sent to your brain so you can hear. This process, although intricate, takes place within milliseconds; humans experience no perceivable delay in hearing sound. Loud sound over-stimulates each component of your hearing function, causing premature decay. An audiometric exam can detect early hearing loss.

Air Pressure and Sinuses

• Your middle ear provides a pathway from the back of each sinus to the back of your throat. By way of a mucous-lined tube called your eustachian tube, mucous, fluid and air travel from your sinuses to your throat. When air pressure changes rapidly, such as during air travel, your ears equalize the air pressure within your body to avoid membrane ruptures. The mucous lining of the eustachian tube absorbs air, causing you to hear a popping sound in your ear.

  Eustachian-tube dysfunction is common among children, resulting in recurring middle-ear infections. A prosthetic tube can be inserted through the eardrum to perform eustachian-tube functions.

Equilibrium

• Your inner ear contains a nerve center for balance. Three semicircular canals sit directly above your cochlea and are connected to your brain by the eighth cranial nerve. Each balance canal contains endolymphatic fluid and nerve endings. These canals detect horizontal and vertical head movements. When your head moves, the endolymphatic fluid stimulates the nerve endings, creating an electrical impulse that is sent to your brain. This function provides your brain impulses regarding body position, movement, trauma and direction.

  Trauma to the head, fast movements and viruses can interfere with the balance function of your inner ear. Vertigo (chronic dizziness) is a common inner-ear condition and can be treated with medication.