CAUSES OF HEARING LOSS: Causes vary, but hearing loss in children can result from infections in the middle ear. Fluid builds up, obstructing sound, and the pressure can perforate or tear the eardrum -- which can usually be repaired through surgery. In adults, the most common cause of hearing loss occurs when the third bone in the middle ear (called the stapes) blocks the transmission of sound waves to the inner ear. There is also noise-induced hearing loss, resulting from exposure to high sound levels, including industrial noise, gunshots, and rock concerts. One of the earliest signs of hearing loss is tinnitus, or ringing in the ears. Tinnitus can be minor or extremely disruptive to people, from almost unnoticeable to catastrophic, interfering with sleep, conversations, and other normal daily activities. To prevent tinnitus it is important to minimize exposure to sustained noises, such as loud music or industrial equipment.
ABOUT THE EAR: 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.
The Acoustical Society of America contributed to the information contained in the TV portion of this report.