Saturday, March 05, 2011

Our hearing

Hearing tests are usually carried out for two main reasons:
  • as a routine part of a baby’s, or young child’s, developmental checks, and
  • to check the hearing of someone who is experiencing hearing problems, or has a hearing impairment.
How the ear works
The ears are highly sensitive organs that allow you to hear sound.
They are made up of three sections:
  • the outer ear,
  • the middle ear, and
  • the inner ear.
Sounds enter the outer ear and pass down the ear canal into the eardrum.
The sound vibrates in the eardrum then travels into the middle ear.
The middle ear is an air-filled cavity that is linked to the inner ear.
The inner ear contains the cochlea (a fluid-filled chamber that is responsible for hearing) and the vestibular system (which helps to control balance).
Your hearing may be affected if there is a problem with your ear, such as a blockage in the ear canal or an infection of the outer ear (otitis externa) or the middle ear (otitis media).
How sounds are transmitted
Sounds are transmitted through sound waves in the air.
After the sound waves have entered the ear, they travel to the nerves in the inner ear, which sends messages to the brain.
The pitch or tone of a sound is determined by how close the waves are to each other.
The closer together the waves are, the more high-pitched the sound is.
Pitch is measured in Hertz.
Hearing tests
Hearing tests are usually painless procedures.
A number of different hearing tests are used to check how well the ears are functioning and their ability to detect different levels of sound.
Two tests that are often used to check the hearing of babies are the:
  • otoacoustic emissions test (OAE), and
  • auditory brainstem response test (ABR).
See the How it is performed section, above, for further information about the OAE and ABR tests, as well as a number of other types of hearing test.
For adults who are having hearing difficulties, a piece of equipment called an audiometer is sometimes used to test hearing.
This test is sometimes called an audiogram or audiometry.
The test checks how well you can hear different types of sound, including soft and loud sounds, and sounds that are high or low in pitch.
So now you know and for why this blog?
Simple we all have ears and it is cool to know a little about them

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