The inner ear is made up of the cochlea and the semicircular canals.
What is the inner ear? The inner ear is the innermost part of the ear, which consist of the cochlea, the balance mechanism, the vestibular and the auditory nerve. Read more in this article about the inner ear’s anatomy, how the inner ear functions and the parts of the inner ear.
The inner ear
Once the vibrations of the eardrum have been transmitted to the oval window, the sound waves continue their journey into the inner ear.
The inner ear is a maze of tubes and passages, referred to as the labyrinth. In the labyrinth can be found the vestibular and the cochlea.
The cochlea
In the cochlea, sound waves are transformed into electrical impulses which are sent on to the brain. The brain then translates the impulses into sounds that we know and understand.
What is the cochlea and what is the function of the cochlea? The cochlea resembles a snail shell or a wound-up hose and is filled with a fluid called perilymph and contains two closely positioned membranes. These membranes form a type of partition wall in the cochlea. However, in order for the fluid to move freely in the cochlea from one side of the partition wall to the other, the wall has a little hole in it (the helicotrema). This hole is necessary, in ensuring that the vibrations from the oval window are transmitted to all the fluid in the cochlea.
When the fluid moves inside the cochlea, thousands of microscopic hair fibres inside the partition wall are put into motion. There are approximately 24,000 of these hair fibres, arranged in four long rows.
The auditory nerve
What is the auditory nerve? The auditory nerve is a bundle of nerve fibres that carry information between the cochlea in the inner ear and the brain. The function of the auditory nerve is to transmit signals from the inner ear to the brain.
The hair fibres in the cochlea are all connected to the auditory nerve and, depending on the nature of the movements in the cochlear fluid, different hair fibres are put into motion.