Ear

The ear is a sensory organ in many animals and in humans. You can perceive sounds with it. As with the eyes, you have two ears, one on the left and one on the right. Because the ears are in two different places, you hear a sound a little differently with each ear. That's why you can tell where the sound is coming from when you hear it.

What you see on the outside of the head is only the pinna. You can still see a little bit of the external auditory canal. Adjacent to the outer ear is the middle ear, which is filled with air. Even further in is the inner ear. There is a fluid in it.

The doctor can see all the way to the eardrum with a special instrument called an ear mirror - but only if the ear canal is not blocked with earwax. The ear mirror looks like a small funnel with a magnifying glass and a torch. Part of the ear is used for hearing. The inner ear also includes our organ of balance.

When the sound waves from a noise reach our ear, they are picked up by the pinna. Through the external auditory canal, the sound waves reach the eardrum. This is a thin skin that vibrates back and forth with the sound waves.

Three ossicles of the middle ear adjust the size of the vibrations. The vibrations are transmitted to the inner ear through a small window protected by a membrane. Behind this oval window, the fluid-filled inner ear begins. To protect the sensitive inner ear from too much sound pressure, the sound transmission in the middle ear can be made worse by two small muscles. The muscles are automatically tensed when the sound pressure is high.

The inner ear is arranged in the shape of a cochlea. Along the snail, the pressure wave is broken down into its frequencies and converted into electrical signals by specialised cells. The nerve fibres of the auditory nerve conduct the electrical impulses to the brain. The brain forms the sound impression we perceive from the impulses, i.e. the information about frequency and volume.