ABOUT HEARING LOSS: Loud sounds can stress and damage the delicate hair cells in the inner ear that convert mechanical vibrations in the air (sound) into the electrical signals that the brain interprets as sound. If exposed to loud noises for a long time, the hair cells can become permanently damaged, producing hearing loss. Noise-induced hearing loss can be caused by two types of noise: sudden bursts, such as firearms or fireworks; or continuous exposure to loud noise, such as motorized recreational vehicles, loud sporting events, power tools, farming equipment, or amplified music. For a person to lose their hearing because of continuous exposure, it would depend on how loud the sound was and how often and for how long they heard it. It takes repeated exposures over many years to cause a noise-induced hearing loss in both children and adults.
ABOUT THE EAR: The human ear has three primary sections: the outer, middle and inner ear. All three work together to help the 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 MYSTERY OF ZEBRAFISH: Scientists are interested in zebrafish because of their curious ability to re-grow the crucial hair cells within their inner ears. Researchers study the fish in an effort to figure out what enables them to do it, with the hope that they may be able to transfer that ability to people.