Protect your ears 
Prevent damage to your ears
Prolonged exposure to loud noise may damage your hearing permanently . Noice doesn' t have to be deafening to make you deaf. Remember : hearing enables us to communicate. Think what a loss of that ability would mean for your social life. Prevent it happening to you.
NOISE INDUCED HEARING LOSS (NIHL)
Very loud bangs can burst your eardrums, but these can be repaired. Similarly , damage to the tiny bones in your ears can be corrected. But Noise Induced Hearing Loss results from damage to the tiny hair cells in your ear and frequent exposure to loud noise caused PERMANENT DAMAGE to these. NIHL IS ESSENTIALLY IRRIEPARABLE AND INCURABLE . Its full effects may only become evident as you grow older. There is no cure : BUT THERE IS PREVENTION , SO READ ON AND TAKE ACTION NOW
HOW YOU HEAR
Sound travels through the air by moving the particles of air between the source of the sound and the ear .
Sound travels in waves, and the outer ear directs the sound vibrations to the eardrum 1
The eardrum vibrates as the sound waves strike it and these are transmitted through 3 tiny bones to the fluid in the inner ear 2
The vibrations in this Fluid cause thousands of microscopic hair cells to produce signals which generate nerve impulses to the brain 3
NOISE = HAZARD
The two key features of noise are frequency and intensity . FREQUENCY refers to the number of vibrations of sound per second or unit time in the air stream , and is measured in Hertz (Hz) .BY INTENSITY we mean the degree of strength with which the sound vibrates the eardrum , and it is measured in decibels (dB) . Noise levels are measured normally in a special scale (A)
which reflects the sensitivity of the ear to certain frequencies .
HOW THIS AFFECTS YOU
With NIHL , this damage is related to the intensity and duration of the noise exposure . BUT, note that the Decibel scale is logarithmic .Therefore :-
90 dB is 10 times the intensity of 80 dB , and 100 times the intensity of 70 dB .
An increase of 3 decibel ( say from 85 dB , to 88 dB ) involves a doubling of sound intensity ...with all that means for your ears .
A reduction of 3 decibel is equivalent to halving the intensity of the noise level ....so 85 dB (A) over an 8 hour period is equivalent to around 83 dB (A) over 12 hours.
TYPICAL NOISE LEVELS
140 jet engine (at 30 m )
130 rivetting hammer
120 grinding metals ( at one m )
110 helecopter landing - helipad diesel room
100 penumatic drill - disco
90 machine shop with heavy plant
80 city traffic
70 private car
60 television in lounge
50 ordinary conversation
40 quiet office
30 quiet whisper
20 countryside at night
10 rustle of leaf
0 threshold of hearing
db (A)
REMEMBER
Exposure without ear protectors to noise levels of 112 dB (A) for a period of one minute will deliver ( day's dose) so KEEP THEM ON.
Prolonged exposure to loud noise may damage your hearing permanently . Noice doesn' t have to be deafening to make you deaf. Remember : hearing enables us to communicate. Think what a loss of that ability would mean for your social life. Prevent it happening to you.
NOISE INDUCED HEARING LOSS (NIHL)
Very loud bangs can burst your eardrums, but these can be repaired. Similarly , damage to the tiny bones in your ears can be corrected. But Noise Induced Hearing Loss results from damage to the tiny hair cells in your ear and frequent exposure to loud noise caused PERMANENT DAMAGE to these. NIHL IS ESSENTIALLY IRRIEPARABLE AND INCURABLE . Its full effects may only become evident as you grow older. There is no cure : BUT THERE IS PREVENTION , SO READ ON AND TAKE ACTION NOW
HOW YOU HEAR
Sound travels through the air by moving the particles of air between the source of the sound and the ear .
Sound travels in waves, and the outer ear directs the sound vibrations to the eardrum 1
The eardrum vibrates as the sound waves strike it and these are transmitted through 3 tiny bones to the fluid in the inner ear 2
The vibrations in this Fluid cause thousands of microscopic hair cells to produce signals which generate nerve impulses to the brain 3
NOISE = HAZARD
The two key features of noise are frequency and intensity . FREQUENCY refers to the number of vibrations of sound per second or unit time in the air stream , and is measured in Hertz (Hz) .BY INTENSITY we mean the degree of strength with which the sound vibrates the eardrum , and it is measured in decibels (dB) . Noise levels are measured normally in a special scale (A)
which reflects the sensitivity of the ear to certain frequencies .
HOW THIS AFFECTS YOU
With NIHL , this damage is related to the intensity and duration of the noise exposure . BUT, note that the Decibel scale is logarithmic .Therefore :-
90 dB is 10 times the intensity of 80 dB , and 100 times the intensity of 70 dB .
An increase of 3 decibel ( say from 85 dB , to 88 dB ) involves a doubling of sound intensity ...with all that means for your ears .
A reduction of 3 decibel is equivalent to halving the intensity of the noise level ....so 85 dB (A) over an 8 hour period is equivalent to around 83 dB (A) over 12 hours.
TYPICAL NOISE LEVELS
140 jet engine (at 30 m )
130 rivetting hammer
120 grinding metals ( at one m )
110 helecopter landing - helipad diesel room
100 penumatic drill - disco
90 machine shop with heavy plant
80 city traffic
70 private car
60 television in lounge
50 ordinary conversation
40 quiet office
30 quiet whisper
20 countryside at night
10 rustle of leaf
0 threshold of hearing
db (A)
REMEMBER
Exposure without ear protectors to noise levels of 112 dB (A) for a period of one minute will deliver ( day's dose) so KEEP THEM ON.
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