What part of the ear is inside the skull?
The delicate ear mechanism is inside the skull, close to the brain. The hard skull protects it from damage. When sound enters the ear it first meets the eardrum, which is at the end of the short tube connected to the outside ear. The sound waves vibrate the eardrum. This vibration moves a series of three tiny bones, called the hammer, anvil and stirrup because of their shape, that increase the movement. These bones are enclosed in a chamber called the middle ear. They pass their movements to another part, the inner ear. This contains a coiled structure shaped like a snail’s shell, oiled the cochlea, where the sound is detected.
How is sound carried to the brain?
Receptor cells in the cochlea turn sound vibrations into nerve impulses and pass them to the brain. The liquid-filled cochlea amplifies sounds as they pass down the spiral. Sensory cells that line the cochlea have small hairs. These are bent as the sound wave vibrates the liquid, causing them to produce nerve impulses. The impulses are passed to the brain along the auditory nerve.
Why do I have an ear flap?
The part of the ear on the side of your head is called the pinna. It collects and directs sounds into the inner part of the ear. The pinna contains rubbery cartilage to strengthen it. Many animals are able to move their ears in order to focus their attention on a particular sound and decide where it is coming from. Human beings no longer have this ability. Instead of moving our ears we turn our head towards a sound that interests us.
Pictures Credit: Google
