Ears Hearing Problems

Hearing is a complicated process involving both the sensitivity of the ear as well as the process to hear and understand speech. Speech includes a combination of high and low frequencies. Depending on where the hearing loss is, that will be where people will experience difficulties.

When people hear correctly, the brain has interpreted the signals brought by the ear, through the canal, through the cochlea and then to the nerves leading to the brain. When something is not working properly along this sophisticated chain, the brain misinterprets and people do not understand. Hearing occurs when sound waves reach the structures inside the ear, and the ear converts the sound wave vibrations into nerve signals that the brain recognizes as sound. The ear consists of three major areas: outer ear, middle ear and inner ear. Sound waves pass through the outer ear and make vibrations at the eardrum. The eardrum and three small bones, namely the hammer the smallest bones in the body of the middle ear, the anvil and the stirrup - amplify the vibrations as they travel to the inner ear.

There, the vibrations pass through fluid in the cochlea, a coil-shaped structure in the inner ear. Attached to nerve cells in the cochlea are thousands of tiny hairs that help translate sound wanes or vibrations into electrical signals that are transmitted to the brain. The sound vibrations of different sounds affect these tiny hairs in different ways, causing the nerve cells to send different signals to the brain. As fluid moves, the ear cells activate the type of nerves that goes to the brain. That is how people distinguish one sound from another.

There are usually two types of hearing loss, sensori-neural hearing loss and conductive hearing loss. Conductive hearing loss is caused by damage to the ear caused by wax build-up, accumulation of fluid in middle ear, ruptured ear drum or infection. This is normally temporary and can be resolved by medical treatment. It can also occur because of some mechanical problem in the middle or external ear. For example, the three tiny bones of the ear may fail to conduct sound vibration to the cochlea or the eardrum may fail to vibrate in response to sound. Otoslerosis is a type of conductive ear hearing loss. It is usually a hereditary loss in which the tiny bones of the middle ear no longer transmit sound vibration properly from the eardrum to the inner ear.

Injuries such as car accidents may break these bones with a similar consequence. Surgery done under a microscope often produces remarkable outcome with this type of loss. Sensorineural hearing loss is caused by damage to inner ear or cochlea. Causes may include drugs, exposure to excessive noise, aging, head trauma, infections or defects. This type of hearing loss is more distressing and is usually permanent. The tiny hair cells which are called cilia, transmit sound through the ear have been damaged. These hairs do not heal, so people should be careful when they are around loud noises! Most hearing loss results from damage to the cochlea and the tiny hairs in the cochlea may break or become bent and nerve cells may degenerate.

• John Palsson
• 30/11/2008, 2:59 AM
• 0 Comments