- published: 20 Jul 2016
- views: 1317
Hearing, auditory perception, or audition is the ability to perceive sound by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear. Sound may be heard through solid, liquid, or gaseous matter. It is one of the traditional five senses; partial or total inability to hear is called hearing loss.
In humans and other vertebrates, hearing is performed primarily by the auditory system: mechanical waves, known as vibrations are detected by the ear and transduced into nerve impulses that are perceived by the brain (primarily in the temporal lobe). Like touch, audition requires sensitivity to the movement of molecules in the world outside the organism. Both hearing and touch are types of mechanosensation.
There are three main components of the human ear: the outer ear, the middle ear, and the inner ear.
The outer ear includes the pinna, the visible part of the ear, as well as the ear canal which terminates at the eardrum, also called the tympanic membrane. The pinna serves to focus sound waves through the ear canal toward the eardrum. Because of the asymmetrical character of the outer ear of most mammals, sound is filtered differently on its way into the ear depending on what vertical location it is coming from. This gives these animals the ability to localize sound vertically. The eardrum is an airtight membrane, and when sound waves arrive there, they cause it to vibrate following the waveform of the sound.
On a train, heading east of here
Where I'll end up, I'm not quite clear
But I can't help myself, I must be settling down
Until they stop this thing, I'll get around
When I hear it's been done before
And I hear it's a simple thing
Then I hear it's quite difficult
And I hear almost everything
Pass through deserts with mountain streams
Outside my window, the scene's serene
The day I find myself I'll be so very proud
And I will not get passed up in the crowd
When I hear it's been done before
And I hear it's a simple thing
Then I hear it's quite difficult
And I hear
Now I'm not trying to cut anyone down
But I know it's been going on too long
Simply doing what you feel
Is the best way not to go wrong
But I know it seems crazy
And it might be a struggle
But I can't believe all this is true
So I'm here, I'm uneasy, and I'm ready to go
And I won't stop until this thing goes round and round
And I can sing like I will never know
When I hear it's been done before
And I hear it's a simple thing
Then I hear it's quite difficult
And I hear
When I hear it's been done before
And I hear it's a simple thing
Then I hear it's quite difficult