How the ear works

INTRODUCTION

Human’s ears are very sensitive and effective when picking up high or low pitch and loud or quiet sounds, it is nearly impossible to make a microphone that is sensitive enough to replicate the human ear, ears pick up sounds as low as 20Hz and as high as 20,000Hz, but even though this sounds impressive some animals can hear higher and lower, for example dog whistles are at the peak of our frequency range and as we get older we can hear theses sounds anymore but a small child be able hear the sounds just as well as a dog.

The human ear has three main parts, the outer ear which includes the auditory canal, the middle ear and the inner ear, 

THE OUTER EAR
the outer ear acts as a glove and funnel by catching the sound and funnelling in towards the tympanic membrane otherwise known as the ear drum, 
the tympanic membrane separates the ear canal or the ‘funnel’ from the middle ear, 

Also the outer ear (pinna) works differently for different frequency sounds, the pinna almost behaves like a satellite dish by directing the sound towards the ears canal, some sounds enter the ear directly other sounds are caught by the pinna and reflected off of the contours of the pinna, these sounds are at a slight delay on entering the ear canal, this delay translates into phase cancellation, Such a delay translates into phase cancellation, where the frequency component whose wave period is twice the delay period is virtually eliminated. Neighbouring frequencies are dropped significantly. This is known as the pinna notch where the pinna creates a notch filtering effect.

THE MIDDLE EAR
the middle ear holds three small bones that help boost and move the sound to the inner ear, these three bones are known as ossicles are singly known as the malleus, the incus and the stapes, 

IN CONCLUSION
The middle ear's job is to mechanically transform sound waves and send the signals on to the inner ear

THE INNER EAR
within the inner ear we have a coiled tissue tube called the cochlea it contains tubes with fluid inside, in one of the tubes minuscule hairs pick up the vibrations that travel through the air and convert them into nerve impulses, in short the cochlea changes sound to neurologic  signals and the auditory nerve which takes sound to the brain. The brain then interprets what the sound is.

All sources of sound send vibrations in the air to the ear, the vibrations get funnelled through the ear, through the external ear canal and strike the tympanic membrane causing it to vibrate, those vibrations are then passed through the ossicles in the middle ear, which then gets sent to the cochlea 

EAR DAMAGE

INNER EAR DAMAGE

Age is one of the main causes of hearing loss but long exposure to loud sounds can cause damage to the cochlea’s hairs or nerve cells which send electrical impulses to the brain, when damaged or gone completely the electrical signals aren’t carried or less are carried to the brain making some higher pitch sounds muffled, it could be heredity meaning that hearing loss is passed through the generations of a family, this is called sensorineural hearing loss and is permanent.

WAX BUILD UP

Earwax can build up and block the ear canals preventing sound waves from passing through the ear. Earwax causes conductive hearing loss, which is easily sorted with earwax removal.

TYMPANIC MEMBRANE PERFORATION

The tympanic membrane or the eardrum can be burst by a vast range of things, such as, really loud noises blasted towards you, sudden changes in pressure for example when  your ears pop due to altitude pressure change, and obviously poking your ear drum with an object can perforate it, a perforated eardrum isn’t able to be repaired.