How We Hear Sounds and Voices
Out of the five senses, hearing is one of the more complicated senses to understand in terms of how it works. Hearing sound means that the ear must translate sound waves into mechanical signals in the form of vibrations, which in turn are translated into electrical impulses so that the brain can process the information. The ear is made out of three parts: the outer ear, the middle ear, and the inner ear.
The outer ear is the part of the ear that is visible when you look at someone. The outer ear includes the pinna (also known as the auricle), the loop of cartilage and skin that is attached to the outside of the head. It works to funnel sound into the auditory canal. The auditory canal, also part of the outer ear, is the part of the ear hole that can be seen when looking at the ear.
Sounds from the auditory canal then encounter the tympanic membrane, aka eardrum, which divides the outer ear from the middle ear. The middle ear consists of the three auditory ossicles (or middle ear bones), the malleus (hammer), incus (anvil), and stapes (stirrup). These tiny bones are responsible for translating the sound waves into vibrations. The vibrations of the bones are picked up by the cochlea.
The inner ear consists of the cochlea, which is a fluid-filled, spiral-shaped structure that has the receptor organ for hearing. Tiny hair cells inside the cochlea translate the vibrations into electrical signals that are brought to the brain through nerves.
For a video describing the process of hearing and the different parts of the ear, check out the “Video about Hearing and How It Works”.
In addition to being responsible for hearing, the middle ear is also responsible for balance.