The ear has three primary sections: the outer, middle and inner ear. All three work together to help the human body detect and process sound.
Sound is simply vibrations in the air. The outer ear picks up sound waves, which travel through the outer ear canal and strike the eardrum. When this happens, the drum begins to vibrate in response. This in turn moves three tiny bones, called the hammer, the anvil and the stirrup. They help transmit the sound vibrations to the inner ear, which is filled with liquid and lined with thousands of tiny hairs that move in response to the sound vibrations. This changes the vibrations into nerve signals, so the brain can recognize and interpret them.
Hearing loss occurs when one or more steps in this complex process are damaged or not functioning properly. Conductive hearing loss mainly affects the outer and middle ear, and results from injury or ear infections. Inner ear hearing loss is one of the most common birth defects in the U.S., affecting 40,000 children each year. Nearly half of inner hearing losses are hereditary. The most common is called otosclerosis, in which new bone is distributed around one of the tiny bones in the middle ear, preventing normal transmission of sound. It can also affect the cochlea in the inner ear, damaging the tiny nerve fibers that detect sound.
Other causes of hearing loss include fluid leakage in the inner ear, and the natural process of aging. Shortly after birth, we slowly begin losing the hair cells and nerve endings in the cochlea, leading to gradual reduction in hearing as we age. Head trauma can damage the internal structure of the ear. Noise can also cause hearing loss, particularly from gunfire, power tools, motorcycles and very loud music.Six Signs You May Have Hearing Loss:
- Asking people to repeat themselves frequently
- Increased frustration and irritability
- Answering inappropriately because a question hasn't been heard correctly
- Socializing less
- Pressure in the ear, or noises such as ringing, buzzing, crickets or steam.
The Acoustical Society of America contributed to the information in the TV portion of this report.