Chany Husarsky B.Y.A. Grade 7 Mrs. Wolman June 6, 2011
A hearing loss can be devastating, especially for a child. Studies show that even a mild hearing loss due to excessive noise can lead to delays in speech and language development and affect a student’s ability to pay attention in the classroom An estimated 12.5% of children, ages 6-19 years old have hearing loss, due to excessive exposure to loud sounds. This type of hearing loss, called noise-induced hearing loss, is usually caused by exposure to loud sounds. Hearing loss can result when nerve fibers in your inner ear, called hair cells are damaged. When these hair cells die they do not grow back, so if you get hearing loss there is no way to get your hearing back. Loud working environments such as, factories, construction sights, and airports, require protection like ear muffs to cover the entire ear. Even every day noises can affect us, we are unaware of the potential danger. Playing loud music, using ear phones, mowing your lawn, or going to a wedding, can affect hearing. 1 I wanted to know, is their a way to avoid noise-induced hearing loss? And if so how? I gathered a few materials that I thought would block out the most sound from entering your ear. My friend and I tested all those materials to determine which one would absorb the most sound. These materials included noise cancelling headphones, earplugs, cotton balls, tissues, hoods, pillows, and fingers. We also wanted to see if we moved away from the source of a loud sound, would the sound level become acceptable. My hypothesis was that if you could not turn down the sound, or move away, fingertips pressed in your ear would be most effective at blocking out the sound. A sound occurs when an object is set into vibration. When the vibration disturbs the air particles they bump into each other and set up a sound wave.2 The loudness of sound refers to the amount of energy flowing in a sound wave. The human ear can hear an enormous variety of sound, from the smallest to the loudest. The decibel scale (dB) named after Alexander Graham Bell, is the unit we use to measure sound. The smallest sound able to be heard by humans is about 0dB which is near silence. At the other end of the scale, a jet engine can be up to 120dB, and a machine gun can be up to 140dB. Sounds at this high level (140dB) can cause instantaneous hearing loss. Anything higher than 120dB can start to cause potential damage. Scientists say that sound level over 85dB can lead to temporary hearing loss. Whether the damage is permanent or not, depends on the sound level, the length of time, and how often you hear the loud sound. 2 The numbering system for decibels is a little complicated. Even though decibels numbers might seem close the actual difference is much greater. The changes in decibels are measured with exponents. A sound that is 40dB is 103
=1000 fold, greater than a sound at 10dB. So a party that is 90dB has a sound level that is 1000 fold greater than a conversation at 60 dB. 3 When a noise is too loud it begins to
