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Unformatted text preview: ©PROJECT OCEANOGRAPHY SPRING 2000 90 ACOUSTICAL OCEANOGRAPHY Unit 2. Lesson 5. Noise Pollution Objectives: Upon completion of this unit, students will understand that noise pollution is more than loud noises. They will also learn what causes hearing damage and that animals, as well as humans, are subject to hearing loss. Vocabulary words: litter, pollution, loudness-related hearing loss, blast trauma What is Noise Pollution? Litter on the side of the road, junk floating in the water, and smokes spewing into the atmosphere from factory smokestacks are obvious forms of pollution. There are other types of pollution that are not as obvious. Noise pollution is one form. What is noise pollution? It is defined as sounds, or noises, that are loud, annoying and harmful to the ear. Often, sound pollution is thought to be a sound so intense that it could shatter glass, or crack plaster in rooms or on buildings. That is not so. It can come from sources such as jet airplanes, constant droning of traffic, motorcycles, high-power equipment, or loud music. How is Noise Pollution Harmful? Sound energy is transferred through compressions and rarefactions. (Reference lesson 1, if necessary.) If the intensity is very large, it can harm human and animal ears, and do damage to physical structures. When sound reaches the human ear, it causes structures to vibrate. Intense vibrations can rupture the eardrum, but more often, loudness-related hearing loss usually develops over time. When sound enters the ear, it is transferred to the brain as a nerve impulse. Each nerve is composed of tiny nerve fibers, surrounded by special fluid within the ear. When intense sound is transferred (as ©PROJECT OCEANOGRAPHY SPRING 2000 91 ACOUSTICAL OCEANOGRAPHY compressional waves) through the fluid, the tiny nerve fibers are destroyed, and hearing loss occurs. Sounds in the frequency range of 4,000 to 20,000 Hz cause most of the damage to the nerve fibers....
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This note was uploaded on 07/31/2011 for the course OCB 6050 taught by Professor Staff during the Spring '11 term at University of South Florida.
- Spring '11