Hearing

Hearing is one of the five senses. The ears are used for detecting (listening to) vibrations in the air known as sounds. Most animals can hear. Most land vertebrates hear through ears. Fish hear in several different ways. Many use their swim bladder to hear, and many use their lateral line.

Anatomy of the ear

Human ear

In humanss, sound travels through three main parts of the ear to be heard. These are the outer, middle and inner ear.

• Outer Ear - This is the part of the ear that we can see called the pinna as well as the inside of the ear called the ear canal. Sound first travels through the pinna and ear canal then to the eardrum at the end of the canal which the sound makes vibrate.
• Middle Ear - Sound continues to travel deeper into the ear and is helped by three of the smallest bones in the body - hammer, anvil and stirrup - to reach the inner ear.
• Inner Ear - Here the sound reaches a small tube shaped like a snail shell, called the cochlea. Inside the cochlea is a fluid, which moves tiny hairs that send signals to the brain which interprets sounds for you to understand and hear

Testing hearing protection devices using artificial head fixtures

How does hearing work?

• The outer ear collects sound waves and works like a funnel to send them through a narrow tube (ear canal) that leads inside the ear.
• At the end of the ear canal is the ear drum (tympanic membrane).
• The tympanic membrane is a thin membrane that vibrates when sound waves strike it.
• It divides the area called the outer ear from the middle ear.
• It is attached to a set of three tiny bones in the middle ear.
• These bones are called the hammer (malleus), anvil (incus), and the stirrup (stapes).
• The bones pass the vibrations of sound waves to a small organ in the hearing part of the inner ear called the cochlea, which is a coiled structure like a snail shell.
• The inner ear is filled with a thin fluid that transmits pressure changes throughout the cochlea.
• Inside the cochlea are tiny hair cells that pick up sound vibrations from the fluid and cause nerve impulses in the auditory nerve.
• The auditory nerve carries the message to the brain, where it is interpreted as sound

This article is a medical stub. You can help WikiMD by expanding it!
Most recent articles Ongoing trials	Wikipedia