HOW HEARING WORKS
How your ear works - Inside the Human Body: Building Your Brain - BBC One
Other things you might like to know
The human hearing range is described by pitch measured in Herz (Hz) and loudness measured in Decibels (dB). We hear many different types of sounds from the gentle falling of leaves to the roar of jet engines. In our industry we all this the audible range.
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Pitch
A person with a normal hearing range can hear between 20 (Hz) to the highest possible without pain 20,000 Hz. Our most sensitive range is between 2000 - 5000 Hz.
At Smiths Hearing Care we measure the pitch your hearing at 125 Hz up to 6000 Hz. This is the range that effects how you hear speech.
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Loudness
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Humans can hear from 0 dB but sounds louder than 85 dB can be dangerous after prolonged exposure. Normal speech is in the range of 20 to 60 dB. According to the World Health Organisation a hearing loss is graded as follows:
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0 - 25 dB Normal hearing
26-40 dB. Mild Loss
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41 - 60 dB. Moderate Loss
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61 - 80 dB Severe. Loss
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Over 81 dB Profound Loss
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At Smiths Hearing Care we test your hearing to measure the quietest sounds you can hear.
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How Hearing Damage Happens
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Deep inside the ear lays the cochlea and within the cochlea there are small nerve cells with thousands of tiny little hairs known as cilia. As we get older these tiny hairs get worn out. A bit like a doormat that is constantly being walked over, the hairs get flattened and the older we get he more worn out they can get. That is why many elderly people don't hear so well. In our industry we call this an age-related hearing loss or presbycusis. Loud noises can also damage the cilia this can happen instantly after hearing an extremely loud noise. The damage can also get caused by overburdening your ears if you are exposed to noises over 80 decibels for too long or too often. The cilia unfortunately do not recover from this damage by themselves; and to this day there have been no medical ways discovered that can repair the damaged cilia.
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See the examples below of some of the everyday things we are exposed to.
Everyday sound levels measured in decibels
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10 Decibels: are almost inaudible - a leaf falling
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20 Decibels: Rustle of leaves
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30 Decibels: Very quiet - whispering
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40 Decibels: Living room, quiet classroom
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50 Decibels: Limited Sound Refrigerator working, car passing
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55 Decibels: electric toothbrush
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60 Decibels: Sound of human voices normal conversation, sewing machine, television
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We talk at a levels of between 20 to 60 decibels
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65 Decibels: Electric Shaver
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70 Decibels: Irritating - Television set on too loud, vacuum cleaner, several people on the telephone.
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75 Decibels: Constant sound - busy restaurant or bar
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Long term exposure to sounds below 80 decibels should not effect your hearing.
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Repeated, long-term exposure to sounds above 80 decibels can lead to permanent damage.
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80 Decibels: Unpleasant - Around 5 hours and 30 minutes a day at this level can cause temporary hearing loss. The weekly limit at this level is 40 hours. Alarm Clock, door bell freight lorries, motor cycles.
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85 Decibels: Loud - Heavy traffic, Food processor
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90 Decibels: Extremely unpleasant - Screaming, yelling, shouting, lawn mower. Around 30 minutes a day at this level can cause temporary hearing loss. The weekly limit at this level is 4 hours
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95 Decibels: Noisy - Drill, violin. Just 10 minutes a day at this level can cause temporary hearing loss. The weekly limit is around 1 hour and 15 minutes.
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100+ Decibels: No more than 1 minutes of unprotected exposure can risk permanent hearing loss.
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100 Decibels: Extremely unpleasant - Machine in a factory, compressor, fighter jet at 300 m. Even a few minutes a day can cause temporary hearing loss. The weekly limit at this level is around 15 minutes.
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105 Decibels: Even Louder - Helicopter close by, large drum
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110 Decibels: Extremely Loud - Rock concert
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120 Decibels: Human voice at its loudest, police siren
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130 Decibels: Thunder Clap
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140 Decibels: Pain Threshold
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150 Decibels: Permanent damage to hearing - Fireworks
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160 Decibels: Shooting with pistol or riffle
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170 Decibels: Shot gun
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180 Decibels: Rocket Launch platform
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191 Decibels: Sound waves become shock waves
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HEARING PROTECTION - IT COSTS NOTHING TO ASK
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CALL OUR CLINIC: 01264 332207 OR MOBILE: 07864 851950
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