The Effects Of Noise Induced Hearing Loss (NIHL)

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Throughout our day to day lives we are exposed to many sounds such as the sound of traffic, coversation, TV, nature and music. More often than not these sounds that we experience are at a low safe level, levels that will not affect or harm our hearing. Unfortunatley when we are exposed to sound levels that are too high or loud sounds over a long period of time there is a chance that the delicate inner workings of the ear can be permanatly damaged. This is known as noise induced hearing loss (NIHL) The effects of NIHL can be noticed either immediately witha sudden dramatic loss of hearing or gradually over a long period of time where it may slowly become harder to understand someone talking in a noisy room. NIHL can affect the hearing of either…show more content…
Sound is localised to the ear by the pinna, travelling down the auditory canal, vibrating the eardrum. The eardrums vibrations are then passed down through the ossicles, three small bones known as the hammer, anvil and stirrup that then transfer the vibrations to the oval window of the cochlea. The cochlea is filled with fluid that when exposed to these vibrations stimulate the sterocilia. This small hair cells "wiggle" along to certain frequencies transferring the vibrations into electrical impulses that are then sent to the brain. If the ear is exposed to noise levels of too high an intensity the sterocilia are overstimulated and many become permanently damaged . (Sliwinska-Kowalska et. All,…show more content…
The unit used to measure the intensity of sound is called the decibel(dB). Sounds that measure up to 75dB are considered to be in the "safe zone". Constant exposure to to sound at these levels are very unlikely to cause any lasting damage to long term hearing. The sound of regular volume conversation measures at around 60dB and the sound of a running dishwasher measures at roughly 75dB. Sounds around the 85dB level are considered a moderate risk to hearing. Exposure at these levels for extened periods of time may lead to some form of damage causing NIHL. Sounds at these levels include heavy traffic and crowded areas at 85dB, active subway stations at 95dB and listening to an mp3 player with ear buds at maximum volume at 105dB in which listening for just 15 minutes can cause permanent damage. Sound at 120dB and above are in the "danger zone". This level of sound is to be avoided at all cost as exposure even for a short pulse will lead to immediate permanent damage. This level includes the sound of ambulance sirens at 120dB, a jet taking off at 140dB and gunshots at 165 dB and above. (Rabinowitz,
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