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Training
Hearing Protection
For safe use of any hearing protection device
It is essential that the user is:
Thoroughly instructed in its use, inspection
& maintenance
Both supervisors & operators should be instructed
by a COMPETENT PERSON
Hearing Protection
MINIMUM TRAINING SHOULD INCLUDE:
1. Why the need to use
2. Noise Induced Hearing Lose (N.I.H.L.)
3. Requirements under current EU regulations
4. Instruction & training in the actual use & maintenance
of the device & a close supervision to ensure that it
continues to be properly used
Hearing Protection
Users should be given regular practice in the
correct fitting of the ear defenders.
Hearing Protection
Noise Induced Hearing Lose (N.I.H.L.)
Definition:
Permanent loss of hearing due to overexposure
to noise
Hearing Protection
• Hearing is more important then we sometimes realize;
• It allows us to hear people talk, music play, the ocean roar and
much more that we want to hear in our surroundings.
• For most of us, these are natural experiences.
• Unfortunately, for some people these are experiences that are
lost, or are being lost, along with the ability to hear properly. What
these people have instead is an injury that seldom can be
repaired.
• The hazard comes from loud sounds or noise that cause
damage, which is stored without being noticed over a long or
short period of time. Much too often, these hazards are ignored.
Hearing Protection
• All sound is made up of pressure waves that enter the ear.
• The ear is a complicated and sensitive apparatus.
• It converts pressure waves to recognizable sound with varying pitch,
intensity and tone quality. This is how it works: Airborne vibrations
enter the outer ear canal, called the auricle, which functions as an
amplifier (for some frequencies).
• The auricle also help us to determine which direction the sound is
coming from.
Vestibule
Auditory
Nerve
Pinna
Cochlea
Outer Ear
Ear
Drum
Eustachian Tube
Hearing Protection
• The sound waves then strike the
eardrum, which starts to vibrate.
• It forms the barrier between the
outer and inner ear.
• The Eardrum is the entire
sensory element in your ear
• It protects your inner ear from
prolonged exposure to loud low
pitch noises
Hearing Protection
• The vibration then travels to the
three tiny ear bones, the
hammer, anvil and stirrup. These
are affected mechanically; at this
point, the strength of the sound
waves has been changed so that
it can be received by the inner
ear.
Hammer
• Sound Waves vibrate the
eardrum, which moves the
hammer, anvil and stirrup
Anvil
Stirrup
Hearing Protection
• The stapedius muscle is
attached to the stirrup; it flexes
when you talk – or if noise levels
exceed 75 dB.
• Sound transfer to the cochlea is
then reduced by maximum 20 dB
in the frequency range up to
2000 Hz.
Hearing Protection
• The cochlea of the inner ear (in combination with the semicircular
canals and balance system) are the next station. It is comprised of
three canals; the middle canal contains the hearing organ.
Cochlea
Hearing Protection
• The organ of hearing is situated
on a membrane and is made up
of 4 rows of hair cells that run
from its base up to the top of the
cochlea.
• The three outer rows of hair cells
serve to regulate sound signals
to the inner row, the actual
microphone system of the organ
of hearing. Each hair cell has its
own frequency.
Hearing Protection
• The hair cells are activated mechanically and start the process
that causes a chemical reaction that leads to electrical signals
being sent to the hearing center in the brain. It is at this point that
we become aware of sound.
Hearing Protection
• What happens if sound waves are too strong or continue
for a long time?
• Exposure to high sound levels (>75 dBA) for several hours
affects the hair cells; the cilia lose rigidity and the cells
swell.
• If this is repeated over time the cells will die.
Hearing Protection
The damage risk follows a “like energy principle”, which shows
that a dose of 80 dB during 8 hours is comparable to 83 dB
during 4 hours (+3 dB = half the time) or 103 dB for 2 minutes,
and so on.
Levels above 110 dBA involve a risk for immediate hearing
damage even if the exposure time is very short.
Hearing Protection
• Impulse noise in industry and construction
• Impulse noises are very dangerous to hearing. Exposure to
one single loud noise is enough to destroy the inner ear cells
of an unprotected ear.
• What is impulse noise?
• Impulse noise is characterized as a short pulse (<1sec) with
very short rise time and a level of at least 20 dB above the
continuous noise level. The total duration is normally shorter
than 0,2 sec.
Hearing Protection
•A rifle shot is in between 0,004 and 0,015 seconds.
Examples of other impulse noise sources:
• gun/rifle shot
• hitting hard materials with a hammer or other tool,
• release of compressed air, explosive devices (can be found
in car air bags)
• nail guns
• punching machines
• metal cutting machines
• pneumatic drills or screwdrivers
Hearing Protection
Aircraft
150 dB
Drill, Compressed Air
120 dB
Drill, Hammer
113 dB
Chainsaw
110 dB
Wood Planer
107 dB
Circular Saw
104 dB
Drill, Electric
102 dB
Welding
95 dB
Grass Trimmer
93 dB
Bandsaw
89 dB
Lawn Mower
88-89 dB
Hearing Protection
• Why are impulse noises more dangerous than other noises?
• The ear and brain need time to identify the level of the noise.
• The duration of a sound signal must be at least 0,3 sec to be
perceived at the right level. Shorter duration noises seem lower to
our ears.
• That means that that the noise level seems lower than it is; we do
not realize that these are harmful to our hearing and we often
disregard the need for protection from these noises.
Hearing Protection
REGULATIONS:
Hearing Protection
Employers are required to:
• Assess the risks to employees from noise at work
• Take action to reduce noise exposure at source If unable to reduce
noise exposure via other methods;
Employers must:
• Provide employees hearing protection and ensure they are worn at the
action levels specified
• Provide hearing protection if requested by employees in the lower
action value range 80-84dB.
Hearing Protection
Provide hearing protection for the upper action values of 85dB and
above
• Ensure legal noise exposure limits are not exceeded
• Identify and clearly mark areas or Zones where wearing hearing
protection is compulsory
• Provide information and training to ensure ear defenders are
properly used and maintained
• Conduct spot checks to ensure hearing protection is worn properly
• Carry out health surveillance where there is a risk to employee
health
Hearing Protection
TO EMPLOYEES?
Employees must:
• Wear hearing protection in clearly marked zones that meet and
exceed the upper action value
• Agree to be been trained in the use and maintenance of hearing
protection
• An employee who regularly fails to use the hearing protection
provided could normally expect to be subject to the company’s
disciplinary procedure.
Hearing Protection
Hearing Protection
Passive Hearing
Protection
Headband
Electronic Hearing
Protection
Neckband
Active
Listening
Helmet Mounted
AM/FM Radio
VMC
Hearing Protection
Passive Hearing Protection
Zone passive hearing protection includes products with varying
noise blocking performance levels, designed to provide a range of
protection in any noise environment.
Zone delivers instant recognition and ease of selection for both
employees and employers via a simple numbering system and
a range of three brightly coloured products.
Hearing Protection
KEY FEATURES OF ZONE PASSIVE
HEARING PRODUCTS:
Intuitive selection - easy identification (yellow, orange, red)
3 distinct levels of noise blocking performance
Clear numbered product labelling (Zone 1, Zone 2, Zone 3)
Optimised cushion pressure provides excellent balance between
comfort and protection
Full integration with other PPE Low profile twin stirrup design maintains
stability and protection
Hearing Protection
Supple cushion materials maintain performance & comfort
Easy size adjustment mechanism
Consistent high calibre attenuation performance ensures low
through life costs
Lightweight earmuff design, Impact resistant cup material.
Approved to global hearing protection standards (CE, ANSI,
AUS/NZ)
Hearing Protection
PASSIVE ZONE EAR DEFENDERS ARE AVAILABLE IN THE
FOLLOWING FORMATS:
• Headband
• Helmet mounted
• Neckband
• Visor Muff Combination
Headband Hearing Protection
• Choice of 3 levels of attenuation performance
• Maintains optimum cushion pressure
• Twin stirrup design maintains stability and attenuation
performance
• Face protection solutions (VMC)
• Impact resistant ABS ear cups
• Simple head size adjustment
• Lightweight design
• Suitable for working with electricity (Dielectric)
• Approved to global hearing protection standards(CE,
ANSI, AUS/NZ)
• Headband comfort pad
• Universal maintenance and hygiene kits
Helmet Mounted Hearing Protection
• Choice of 3 levels of attenuation performance
• Universal 30mm attachment posts
(25mm also included, 15mm optional)
• Maintains optimum and even cushion pressure
• Twin stirrup design maintains stability and attenuation
performance
• Airing and park positions
• Low profile - reduces snagging risk
• Lightweight design
• Simple head size adjustment
• Impact resistant ABS ear cups
• Suitable for working with electricity (Dielectric)
• Approved to global hearing protection standards (CE,
ANSI, AUS/NZ)
• Universal maintenance and hygiene kits
Neckband Hearing Protection
• Choice of 3 levels of attenuation performance
• Maintains an effective seal when wearing head protection
• Choice of 3 levels of attenuation performance
• Maintains optimum and even cushion pressure
• Twin stirrup design maintains stability and attenuation
performance
• Low profile
• Lightweight design
• Velcro crown securing point
• Easy to adjust for the perfect fit
• Impact resistant ABS ear cups
• Approved to global hearing protection standards (CE,
ANSI, AUS/NZ)
• Universal maintenance and hygiene
Visor Muff Hearing Protection
• Choice of 3 levels of attenuation performance
• Lightweight, PPE combination protection system
• Additional EN166 face protection (Polycarbonate or Nylon
Mesh visor options)
• Available complete with hearing protection or VMC
conversion kit
• Wraparound visor design for maximum protection
• Easy to fit, adjust and replace visors
• Retractable visor mechanism
• Headband construction maintains optimum cushion
pressure
• Impact resistant ABS ear cups
• Twin stirrup design maintains stability and attenuation
performance
• Headband comfort pad
• Universal maintenance and hygiene kits
• Extends range of application without compromising safety
Hearing Protection
Electronic Hearing Protection
Zone active listening and AM/FM radio ear defenders means
there is no longer a reason for the temporary, potentially
damaging short term removal of ear defenders. The benefits
of electronic protection are clear, a safe, motivated workforce
with improved moral and productivity without compromising
safety.
Electronic Hearing Protection
KEY FEATURES OF ZONE ELECTRONIC
HEARING PROTECTION SOLUTIONS (ADDITIONAL TO PASSIVE)
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•
•
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Easy to operate controls
Hi-Fi sound quality & speech amplification
Enables user to communicate effectively
Enables user to hear vital warning signals
Improves productivity & morale
Reduces feelings of isolation
Protects against damaging and unexpected impulse noise
Long duration use from standard alkaline batteries
Electronic Hearing Protection
KEY FEATURES OF ZONE ACTIVE HEARING PRODUCTS
(COMMON WITH PASSIVE)
• Intuitive selection - easy identification (yellow, orange spacers)
• Full integration with other forms of PPE
• Optimised cushion pressure provides excellent balance between
comfort and protection
• Low profile twin stirrup design maintains stability and protection
• Consistent high calibre attenuation performance ensures low
through life costs
• Headband and helmet mounted variants
Electronic Hearing Protection
KEY FEATURES OF ZONE ACTIVE HEARING PRODUCTS
(COMMON WITH PASSIVE)
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•
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Supple cushion materials maintain performance & comfort
Simple size adjustment mechanism
Lightweight earmuff design
Impact resistant cup material
Optimum cushion pressure
Flexible helmet mounted attachment system
Helmet mounted – standby and parked positions
Headband comfort pad
Electronic Hearing Protection
ZONE ACTIVE HEARING PRODUCTS ARE AVALIBLE IN
FOLLOWING FORMATS:
• Alert Zone
• Focus Zone
Alert Zone Ear Defenders
• The Alert Zone “active listening” ear defender with intelligent
Electronic Protection System
• Safeguards wearers against the dangers of short-term removal by
preventing feelings of isolation; enabling the wearer to remain fully
aware and alert to their surroundings.
• Vital warning signals can be heard and optimum speech clarity is
received from verbal communication, without compromising
protection.
Alert Zone Ear Defenders
•Active listening microphones provide perfect
directional hearing and spatial awareness
•Sound amplification up to 8 dB(A) delivers
optimum speech clarity
•Electronic Protection System (EPS) limits speaker
sound level to 82dB(A)
•Easy connection for com-radio, mobile phone,
ipod etc.
•Stereo/Stereo and Stereo/Mono connection
cables included
Alert Zone Ear Defenders
• Supplied complete with 2 x AAA batteries (approx
400hrs use)
• Zone 1 level passive performance
• Headband or helmet mounted models
• Non conductive dielectric design
• Twin stirrup design distributes ear cup pressure
evenly for an excellent seal
• Flexibility to integrate with Protector head and
face protection
Focus Zone Ear Defenders
Focus Zone AM/FM radio ear defender has been designed to
counteract feelings of isolation and to improve the morale and
productivity of people working continuously in hazardous
noise.
Focus Zone is suitable for a wide range of industrial
applications and enables the wearer to listen to their preferred
radio station and to connect an external sound source
including, mp3-players, mobile phones or com-radios, without
compromising protection.
Focus Zone Ear Defenders
• Integrated AM/FM stereo radio
• Ergonomic one handed operation
• Electronic Protection System limits speaker
sound level to 82 dB(A)
• Supplied complete with 2xAA batteries (approx
300hrs use)
• Easy connection for com-radio, mobile phone,
ipod etc.
• Stereo/Stereo connection cable included
• Zone 2 level passive performance
• Easy to install aerial and amplifier accessory
• Headband or helmet mounted models
• Non conductive dielectric design
• Twin stirrup design distributes ear cup pressure
evenly for an excellent seal
• Flexibility to integrate with Protector head and
face protection
Accessories & Spares
Self-adhesive antibacterial hygiene pads
are available. They absorb heat and make
the ear defender more comfortable
and hygienic to wear.
New cushions and first layer absorbent.
Should be changed at least every 6 months.
Standard for all Zone ear defenders
Accessories & Spares
Zone can be quickly adapted for 30mm, 25mm
or 15mm helmet accessory slots.
30mm and 25mm attachment posts are included
in the box and all sizes are available as spare parts.
Zone headband versions can be specified in or
easily converted into a Visor Muff Combination.
Accessories & Spares
Some buildings with lots of concrete and/or steel can sometimes
block out FM signals, leading to poor radio reception.
An aerial and amplifier is available for maximum amplification
of the FM range 88 – 108 MHz.
Each slave aerial covers a radius from the vertical antenna of
approximately 20–50 meters, depending on the premises.
A total of 3 slave aerials can be connected to each amplifier.
Meanings
Frequency - The rate at which a sound source oscillates is the
frequency of the sound it produces; this is often quoted in hertz (Hz)
or cycles per second (cps). An audible frequency is characterized as
a periodic vibration whose frequency is audible to the average human
ear. While the range of frequencies that any individual can hear is
largely related to environmental factors, the generally accepted
standard range of audible frequencies is 20 to 20,000 hertz.
Frequencies below 20 Hz can usually be felt rather than heard,
assuming the amplitude of the vibration is high enough. Frequencies
above 20,000 Hz can sometimes be sensed by young people, but
high frequencies are the first to be affected by hearing loss due to
age and/or prolonged exposure to very loud noises.
Meanings
SNR - Signal-to-Noise Ratio - compares the level of a desired signal
or noise to the level of background noise. The higher the SNR rating,
the less environment or background noise can be heard.
An SNR value has come to indicate the average level of protection a
device can offer across the frequency level between 63Hz and 8000Hz.
As a broad measure of average protection, there is not enough information
contained within this figure to make definitive comparisons between
hearing protectors, like HML analysis it can only be used as an indicator
of the general noise level that the protector is designed to protect against
and the results of an audiometer test / noise attenuation survey will more
accurately assist the selection of an appropriate hearing protector.
Sometimes SNR is also referred to as Simplified Noise Rating,
Single Number Rating or Single Noise Rating.
Meanings
NRR – Noise Reduction Rating – US equivalent of SNR that
estimates the amount of protection achievable by 98% of users
in a laboratory setting when hearing protection is correctly fitted.
Although not a 100% accurate real world rating, it provides a
commonly used single number for attenuation performance in the US.
The NRR is derived from an extensive calculation that involves
laboratory testing against at least 10 people across a range of
frequencies.
Two standard deviations and several corrections and cushions
are factored in to take account of the individual user variation and
to make the NRR applicable to a broader population.
Meanings
H.M.L – High, Medium, Low
H.M.L attenuation figures indicate the protection profile of a
hearing protection device. These figures offer a simple
method for comparing the noise reduction performance
offered by an ear defender at High, Medium and Low frequencies.
Attenuation - is the reduction in amplitude and intensity of signal.
Attenuation is usually measured in units of decibels.
Mean Attenuation – Average reduction in amplitude and intensity
of a signal/noise. EN352 states that the mean attenuation value
of a hearing protection device is derived from the mean difference
in decibels between the threshold of hearing with and without the
hearing protector in place, for a panel of test subjects, which in the
case of EN352 is 16 people.
Meanings
St.dev. – in statistical terms describes variance from a mean value.
Std.dev. in a hearing protection devices attenuation performance table
shows the variance from the mean attenuation for the 16 subjects.
Generally a small variation would indicate that the hearing protector
was suitable for a wide range of head size.
APV - Assumed Protection Value is calculated when you subtract
the standard deviation from the mean attenuation value.
The 16 persons tested under EN352 with a particular hearing
protection device are calculated to be equivalent to a given % of the
population. (not sure exactly what %) 84% of the population covered
take the mean of these 16 – 1 std deviation.
In ANSI they subtract 2std deviations.
Hearing
• 20 Hz Sweep
• 1000 Hz
• 5000 Hz
• 10000 Hz
• 15000 Hz