To understand what is the hearing loss and what consequences it brings, you need to get to know the functioning of the hearing organ. The ear receives sound waves, converts then into bone vibrations, and then into nervous impulses, which are interpreted in our brain. Just one disability of the link in this chain is enough to have a problem with hearing.
The hearing organ is responsible for the reception of stimuli. It receives sounds focusing sound waves. Then it transforms them into nervous impulses.
The hearing organ consists of 3 parts:
1.    Outer ear
•    The outer ear consists of the pinna, ear canal and tympanic membrane, which separates it from the middle ear.
•    It receives sound waves and directs the tympanic membrane, which starts vibrating under pressure.
2.    Middle ear
•    The middle ear is connected with the throat via Eustachian tube, which equalizes the pressure inside it (there is air inside the ear).
•    In the ear cavity there are 3 bones: malleus, stapes and incus.
•    Muscles adjoin the bones (stapes and eardrum tensor), which get activated when the sound reaches the ear. Thanks to their work the too large pressure gets reduced before the sound reaches the inner ear.
•    “Leverage”, which is formed by the bones, transfers vibrations from the eardrum to the fluids in the inner ear.
3.    Inner ear
•    The inner ear consists of the balance organ and the cochlea. As the very name suggests it has a shape of a twisted shell. There are 2 “windows” inside.
•    In the oval window there is placed the stapes base, which acts like a piston, which moves the fluid of the inner ear.
•    The movement of the fluid activates about 20 thousand hair cells, which send impulses through nervous fibres. They are interpreted as sound in the brain.