The Human Ear

The human ear is a miniature receiver, amplifier and signal processor all in one. The ear is split into three main sections the outer ear, middle ear and the inner ear. The ear also plays an important part in how we maintain our balance and how we perceive things like distance, room structures and atmosphere. Hearing is one of the five human sense's and is essential for how we communicate and live our modern lives. The ears pick up sound waves which travel through the air and through different materials and this is how sound is felt rather than seen.

  The outer ear acts as a funnel and sound waves are collected and then sent directly down the ear canal to the eardrum. The fact we have two ears means that two signals are sent to the brain a split second apart and at a slightly different pressure, and the brain can then detect these differences and therefore work out the direction the sound comes from. Sound waves entering the ear travel along the ear canal and strike the eardrum, which has a tightly stretched membrane covering causing it to vibrate. These vibrations are then picked up and then transmitted by the three ear ossicles. The three ear ossicle are the three smallest bones in the human body. The oval window of the middle ear is a membrane covered hole and the vibrations from the ossicles amplify the sound as the oval window is much smaller than the eardrum. The middle ear is also connected to the throat via the back of the mouth through the Eustachian tube, which is where the air pressure is equalized. After the vibrations of sound are passed through the oval window of the middle ear they are then transmitted to the cochlea of the inner ear.

The cochlea is a long, spiral shaped, fluid filled tube that is layered with sensory hair cells. The hair cells in the cochlea work differently to each other as they are all sensitive to a different frequency. The different hair cells range from shortest to longest along the length of the cochlea. The very short...