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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) • • • • • • • • 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) • • • • • • • • 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