Noise is an unwanted sound, loud sound, a wrong sound in a wrong place at the wrong time. Sound has four characteristics-loudness (measured in decibels- dB ), pitch ( measured in Hertz-Hz ), periodicity and duration.
Sound higher than 85 dB in loudness is noise, while sound higher than 120 dB is very loud noise; this can destroy the inner ear.
Exposure to noise can occur in different locations- factories, night clubs, airport vicinities, parties, railway stations, high ways etc. A lot of Nigerians are exposed to hazard noise for more than eight hours a day in manufacturing outfits. It is not a routine to measure noise levels in plants across the country; automobile plants and other manufacturing plants.
Fireworks and firearms are also sources of noise.
There are recommended duration for exposure to noise: 8 hrs.’ exposure to noise up to 90 dB, 4 hrs.’ exposure to noise up to 95 dB and 2 hrs.’ exposure to noise up to 100 dB. Any noise above 115 dB is forbidden.
Noise is hazardous, it is injurious to health as the following will show.
Very loud sudden noise can destroy the ear drum and the inner ear, this can lead to temporary or permanent deafness. Such noise is usually above 120 dB.
2. Ringing Noise in the Ears.
Ringing in the ears otherwise called tinnitus can be caused by loud noise. This ringing noise in most cases is heard only by the sufferer, occasionally, an examining health practitioner can hear it.If there is no underlying disease, ringing in the ear alone is a very big nuisance.
3. Reduced Performance/efficiency
Noise reduces concentration, brilliance, and efficiency. Students whose schools are located near airports have been found not perform as well as those whose schools are located in more quiet areas.
Very loud noise can cause loss of memory.
4. High Blood Pressure
Noise can make your heart beat faster and at the same time, the blood vessels contract more. These two can contribute to a rise blood pressure.
5. Increased Risk of Stroke
Blood vessels can respond to loud noise by narrowing (reducing the inside), if this narrowing is too much and happens to small vessels in the brain, blood supply to that part of the brain can be affected. This is stroke.
Noise causes sleeplessness or poor sleep. It causes annoyance, irritation. Lack of sleep and irritation can cause stress.
Very loud noise, above 140 dB, has been known to cause abortions in early pregnancy