Hearing protection explained

Ever wondered what all those important-sounding compliance numbers and letters mean when you buy a set of ear defenders? And more to the point, why they matter? The makers of CENS have the answers...

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earing protection is an essential requirement for shooters of shotguns, rifles and handguns. Even centrefire rifles fitted with moderators can produce sound levels capable of damaging hearing. Equipment worn for protection against the harmful effects of noise is known as Personal Protective Equipment (PPE). For over 20 years it has been a legal requirement throughout Europe for manufacturers of PPE to ensure their products comply fully with Directive 89/686/EU (PPE). The Directive defines the Essential Health & Safety Requirements for PPE and the steps manufacturers must take to ensure conformity, enabling them to apply the ‘CE’ mark before legally placing the product on the market.

Typically, part of this process is for manufacturers to provide evidence of product testing to regulated ‘harmonised’ standards. For earplugs and earmuffs, the relevant standards are published in a range referred to as EN352 according to product type.

For example, traditional earplugs are covered by EN252-2 alone, whereas electronic earplugs (level dependent) require additional testing to EN352-7. Due to the complexity of equipment and level of expertise required to perform such testing, it is usual for this work to be carried out by specialist testing laboratories approved to national standards. Test results, along with other technical documentation, must then be assessed by an accredited Notified Body before an EC test certificate is issued to the manufacturer. Results of testing to EN352 are used to provide attenuation data for the end user so they can assess suitability of PPE for the intended use. Attenuation data, along with details of where the product was tested and approved and instructions for use, must be provided with the PPE. Attenuation data must be expressed in the HML and SNR formats. HML provides the assumed attenuations in the individual High, Medium and Low frequency ranges; SNR is the Single Number Rating giving an overall assumed attenuation rating for the complete frequency range.



Gamekeeper Geoff Garrod says his custom-made earplugs are so comfortable that he forgets he is wearing them


Different standards


In the US, different methods of testing and result calculations are used for noise protection equipment. The US attenuation results are quoted as NRR (Noise Reduction Rating), there is no direct correlation with EU SNR results and products should not be compared across these formats. Hearing protection with only NRR attenuation data cannot be legally placed on the market within the EU. There is, however, an additional US test procedure with no EU equivalent that is highly relevant to gunshot noise (high impulse noise). IPIL or Impulse Peak Insertion Loss testing to ANSI S12.42-2010 provides attenuation data at impulse peak levels. These results can then be used to calculate the number of allowable exposures per day to different levels of impulse noise.






George Digweed’s view


CENS is used by thousands of shooters worldwide, including many who are highly renowned and recognised. CENS Brand Ambassador George Digweed MBE (26-time world champion clay shooter) says: “I have been using my CENS since 2012, and would not be without them in the field. Not only do my CENS ProFlex digitals provide excellent noise suppression and the ability to hear ambient noise such as wing beats, they still allow you to have a normal conversation without the need to remove them. This makes them an invaluable part of my game shooting equipment.”

Beware misleading claims


Following the correct procedures to legally place hearing protection devices on the market requires considerable time and financial investment by the manufacturer. It would appear that many companies fall short of their legal obligations and fail to have their hearing protection products tested and certified. Very often these products will have misleading or ambiguous information with no reference to origin. Phrases such as ‘attenuation UPTO’ and ‘Maximum Attenuation’ will be used. These products should be avoided. Some products may only show data for a third-party filter used within the product, misleading the end user to believe the complete product is compliant. If your product does not carry the SNR rating, CE and EN352 marks, then you will most probably be purchasing a cheap imported product that has not even been tested, and as such there will be no guarantee that they will provide safe protection, or any protection at all.

Many cheap or fake devices fail to provide adequate instructions for use – this is often the way to spot non-certified products. If in doubt, ask to see the manufacturer’s EC Declaration of Conformity to PPE Directive 89/686 and EC Type-Examination Certificate. These legal documents should be freely available; validity can easily be checked with the Notified Body identified on them. The responsibility for ensuring that the Directive is adhered to falls upon the manufacturer. The Directive is enforced in the UK by the local authority Trading Standards Service. Failure to comply can lead to up to three months in prison and/or a fine of up to £5,000. Furthermore, manufacturers can be required to recall and replace any equipment found to be faulty.


Olympic Skeet shooter Amber Hill is an advocate of CENS hearing protection

CENS products and compliance


All CENS devices are tested to EN352 and are certified as PPE; they are also IPIL tested to ANSIS12.42-2010. The PPE Directive is currently being upgraded to the more legally binding PPE Regulation (EU) 2016/425, reflecting new technology, enhancing consumer safety and ensuring fair competition between manufacturers. It is of note that hearing protection PPE is re-classified from intermediate Category II to complex risk Category III. The Regulation was adopted throughout all EU member states in April 2016 and will come into full force in 2018.

Custom-made CENS® devices are manufactured to exactly match the contours of the ear to provide extremely comfortable hearing protection. By effectively blocking the outer ear and ear canal, these devices prevent high air-conduction sound pressure levels from reaching the eardrum. This prevents acoustic trauma, thus injury, to the hearing mechanism in the inner ear due to very loud noise.

As CENS earpieces are custom-made to be a perfect match to your ear, they provide highly effective noise reduction, helping to protect your vital hearing.



Damage limitation


Gunshot noise is around 120dB to 180dB, depending on gun and ammunition, and even being exposed to 100dB sounds for longer than 15 minutes per day will start to cause permanent damage to your hearing. The louder the sound, the sooner the chance of permanent hearing damage. Symptoms such as continued ringing in the ears or temporary hearing loss are signs that you should be using hearing protection. Without some form of hearing protection, the sound of a gunshot at close range will irreversibly damage your hearing for life, and that’s a fact! CENS custom-made earpieces provide amazing noise reduction, effectively reducing gunshot noise to a safer level.



CENS electronic hearing protection


These incorporate an electronic sound reproduction system. At low levels of noise the sound detected by a microphone on the outside of the device is relayed to a loudspeaker. At higher levels of impulse noise the electronic circuit cuts out, leaving the inherent attenuation of the device/ear-moulding to provide the protection. CENS devices are digitally programmed and optimised for various shooting styles and disciplines. The digital algorithm which is implemented in the devices has been researched and developed after many years of field studies by technical personnel and shooters at Puretone Ltd (the designers and manufacturers of CENS). The result is an unparalleled range of devices to suit most budgets.

CENS is proud of its commitment to protecting people’s hearing all over the world, and the reputation that it has developed as a result of professionally testing and marketing its devices.


Hearing Protection Sound Levels
 
CENS® is a registered trademark of Puretone Ltd. | CENS® module is protected by EC Design Registration No. 001861998-0001 |
Norwegian Design Registration No. 083344 | South African Design Registration No. 2011/01813 | US Design Patent Pending
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