Steady Exposure To Noise Above 80 Db example essay topic

... Noise, Noise Pollution and It's Control What is noise? Noise is the background disturbance caused by signals that are random and unpredictable. This can be called sound which is the sounds of everyday life. It is generated when a disturbance sets the air moving. We hear sounds when 'tiny vibrations in the air called sound waves strike our eardrums.

A sound wave consists of air molecules vibrating backwards and forwards. The molecules are crowded together in some areas producing places of high pressure and spaced out in others producing regions of low pressure. These waves move through the air spreading out from the source of the sound. These sound waves carry the sound to your ears.

A high pitched sound makes the air vibrate backwards and forwards more times per second than a low pitched sound. The number of vibrations per second is called the frequency and is measured in hertz (cycles per second). Humans can't hear sounds with frequencies above about 20,000 hertz or below about 30 hertz. Decibels Loudness is measured in decibels and the symbol for a decibel is dB.

The loudness of a sound depends on how close you are to its source. Decibels are named after Alexander Graham Bell. 30 dB carries ten times more power than 20 dB. The sound of a person speaking one metre away is 50 dB and the sound of traffic is about 75 dB. People who are exposed to sounds of over 80 dB for long periods of time risk damaging their hearing. Beyond sounds of 140 dB it can be very dangerous.

Ways in which noise can damage hearing Many noises can damage hearing, for example traffic or amplified music played at high volumes in confined rooms. The most consistent finding in noise related hearing loss is damage to the sensory or hair cells. Even when the noise level is not dangerous it can be distracting which could be dangerous in it's own way. Exposure to excessive noise can impair working efficiency and temporary or permanent hearing loss may occur, depending on the loudness or the intensity of the noise, it's pitch or frequency, the length of exposure and the vulnerability of the person.

If the air is vibrating backwards and forwards a lot of times per second it strikes the eardrum faster which can damage it. If the decibel level is over 140 dB it can cause the eardrum to burst. Sound Levels Up until a sound level of 80 dB no damage to the hearing will occur. At a constant sound of 80 dB sound is annoying, but steady exposure to noise above 80 dB can be potentially dangerous. If sounds reach above 140 dB the eardrum could burst. Many household appliances are loud enough to be in the 85 - 90 dB range for example a vacuum cleaner at 85 dB or a chain saw at 100 dB.

Teenagers are at a very high risk of damage to hearing because they are exposed to very high sound levels for hours at a time. Walkmen and personal CD players are very popular and playing them too loud can cause noise induced hearing loss. Also jogging or cycling with a walkman or personal CD player can be dangerous if the volume is too loud because this will cause adrenaline to be produced which will limit oxygen delivery to the ear and blood flow may become restricted causing the ear to be damaged. Shooting is another activity which can be damaging to the ear if earplugs are not worn as the sound of a gunshot can be as loud as 140 dB. Protection from noise Airports, busy roads and railways can create a lot of noise so people living nearby need protection in their homes. The main item of protection is secondary glazing which helps keep noise levels to a minimum.

At night time people could wear ear muffs or ear plugs to keep as much noise as possible out. Noise is becoming an ever growing problem and new protection needs to be found... Secondary glazing. Earmuffs. Re-direction of noise source e.g. re-route traffic and aircraft. Muffling of noise source e.g. Jet engine hush kits.

Curfew times e.g. Airport shuts at 10 pm. Legislation e.g. Noise limits reduced each year for machinery and transport Work in factories Workers in factories are often exposed to high noise levels from equipment such as drills or other loud machinery. Employers need to protect their employees hearing so they can work their best. To protect workers hearing they are not allowed to be working on a noisy piece of machinery for too long at a time.

Also while using the machinery protective ear muffs must be worn to keep noise to a minimum. DIY and gardening can often cause noise pollution for example a lawn mower has a decibel level of 90 dB, a dish washer has a level of 60 dB and even leaves rustling has a level of 40 dB. There is not much you can do to protect yourself from the sound pollution of these activities apart from wearing ear muffs whilst doing them or to install double glazing to decrease the noise of other people doing them. Unavoidable noise There is always noise you can't avoid having in your building, for example the noise from a washing machine or blow drier.

The noise level can be kept to a minimum however by only using these pieces of equipment when it is really necessary. This way you don't get any more noise pollution than you really have to. Sound reduction To reduce the level of sound in terraced houses and music practice rooms it is often impractical to use distance to reduce the noise. The following methods can be used: .

Double / triple glazing. Wall insulation e.g. Cavities and Rock wool. Separating living space with general space e.g. Bedrooms adjacent to hallways General protection from noise. Hearing protection should always be worn when there is exposure to loud noise. People who work in noise need to give their ears a rest after being in a noisy environment. When using a walkman or personal CD player exposure should be limited on a daily basis.

Any exposure to loud noise should be limited. You should have your hearing checked regularly to test for any loss of hearing. When buying any household appliance you should search around for the quietest model to reduce noise pollution Laws COMMISSION DIRECTIVE 73/350/EEC expanding on legislation regarding silencers. COMMISSION DIRECTIVE 84/372/EEC amended these requirements to allow for better measurement of sound levels in urban traffic conditions in line with UNE C Regulation 51. MOTORCYCLES: COUNCIL DIRECTIVE 78/1015/EEC set limits on sound levels from motorcycles, laid down requirements for exhaust silencers systems and established a harmonised testing procedure for implementation in Member States. Noise levels for engines with a capacity of less than 80 cm 3 were limited at 78 dB (A) or below, while those over 500 cm 3 were set at 86 dB (A) or below.

DIRECTIVE 87/56/EEC reduced the number of motorcycle categories to three and set a two-stage reduction in the noise limit values for each category. Motorcycles under 175 cm 3 were restricted to a limit of 82 dB (A) by 1988, to be reduced to 80 dB (A) by 1993. COMPRESSORS ~N COUNCIL DIRECTIVE 84/553/EEC sets noise limits and requirements for the issue of an EC type-examination certificate for compressors. TOWER CRANES ~N COUNCIL DIRECTIVE 84/534/EEC sets noise limits and requirements for the issue of an EC type-examination certificate for tower cranes. WELDING GENERATORS ~N COUNCIL DIRECTIVE 84/535/EEC sets noise limits and requirements for the issue of an EC type-examination certificate for welding generators.

POWER GENERATORS ~N COUNCIL DIRECTIVE 84/536/EEC sets noise limits and requirements for the issue of an EC type-examination certificate for power generators. LAWNMOWERS ~N COUNCIL DIRECTIVE 84/538/EEC sets noise limits and requirements for the issue of an EU type-examination certificate for lawnmowers EXCAVATORS, DOZERS AND LOADERS ~N COUNCIL DIRECTIVE 86/662/EEC sets noise limits and requirements for the issue of an EU type-examination certificate for earthmoving machines used on engineering and construction sites. SUBSONIC JET AIRPLANES ~N COUNCIL DIRECTIVE 80/51/EEC established limits on noise emissions from subsonic airplanes based on standards set by the International Civil Aviation Organisation. HOUSEHOLD APPLIANCES ~N COUNCIL DIRECTIVE 86/594/EEC governed the provision of information on the airborne noise levels of household appliances. Does not apply to specifically industrial or professional appliances or those integrated into buildings such as home heating systems etc. Under Section 51 of the Local Government Act 1963 it is an offence to make any noise or variation which is so loud, continuous or repeated or at such time as to give reasonable cause for annoyance to neighbours.

It also provides for procedures for securing the abatement of the noise. Conditions may be attached to planning permission for developments to reduce emissions from and / or intrusions into structures by noise. Building regulations in 1992 provide for greater insulation to reduce noise intrusion into new houses. Noise reduction inside the school Carrying out a survey over the school the noisy areas seem to be: . The basement - any footsteps or other such noises from the hallway above and MO 2 can be heard from the basement below...

The Reading Room - From the reading room you can hear all the sounds of people on the main landing below and coming up the stairs to the library. Also any sound made in the reading room seem very loud and echoes... The Canteen - like the reading room there is not much furniture in the canteen and any sound made seems very loud and echoes. All of these rooms have little furnishings and thin walls. To reduce sound levels the walls should be made thicker or insulated. Double glazing could be added or more furnishings should be out in the room.