One of the strongest features of protective ear muffs is their ability to reduce the levels of destructive noise intensity by close to 98% of their original values. The tests conducted on these devices are said to be in conformance with the ANSI S-3.19 and CE-EN-352.1 standards. The ANSI standards consider the Noise reduction rating (NRR) as the main criterion for evaluation of the quality features of the protective ear muffs. They are applicable for industrial applications as well as sporting and hunting applications in which shooting is involved.
Safety Features of Protective Ear Muffs
Top priority of safety is given to the ear canal coverage of the protective ear muffs. They are designed with the components like the ear cups, inserting foam pads, cushion and cover, headband and the padding provided for the headband. They are common for all types of ear muffs. Added features like electronic filters and battery support are provided for the active types of devices.
- The basic design of protective ear muffs is based on the structural construction of the ear cups. They need to be flexible in movement and angular rotation to considerable extent. For this purpose the swivel type of design is mostly recommended. They ensure maximum protection and convenience for the users. They need to be supported by the design of headband which must have flexible features. The distance between two ears should be variable with the help of adjustable screws. They can make the two parts slide into each other, providing the perfect fitting measurements for all head sizes.
- The inserts and foam padding within the swivel cup interiors should be firmly attached without sliding away. Usage of glue may not work as it can produce discomfort while wearing. Hence they are fitted with the help of adjustable screws. They are designed to absorb maximum noise volumes when exposed to high pitch volumes. They can also work for extended hours (more than 8 hours at a stretch) with the same levels of efficiency under variable environment conditions.
- The sort of noise emanating from the external environment may be varying in the low or medium frequency levels. This range is said to be from 64HZ to 8000HZ. On the other hand you can come across impulsive noise generated from muzzle blasts. They are generated by the firearms. Their intensity is often more than 164DB. For such noise, the NRR tests may not be sufficient. They need to be supported by Rear Ear Attenuation at Threshold. By analyzing the results from combinational tests, the quality parameters of the protective ear muffs are determined.
- The Environment protection Agency of the USA has introduced certain specific de-rating parameters for the NRR which could also be used for the protective ear muffs. The constant value of 7 is used to subtract the net NRR value under real time conditions. Any value which falls in the range of 30DB and above is said to be good enough to rate the protective ear muffs as reliable and safe. ClearArmor 141001 Shooters Hearing Protection Safety Ear Muffs are tested to conform to all the American and European standards for protective ear muffs.