- Polystyrene and synthetic foam cups
- ABS headband adjustable in height
- Low pressure pads
- CE approved
- Weight 158g
EN352-1 Hearing protection: Ear-muff
High frequency attenuation H 30
Medium frequency attenuation M 27
Low frequency attenuation L 17
Noise Regulations require employers to take action about extreme noise at work. Ear defenders or ear muffs are PPE (personal protective equipment) designed to protect the wearer usually with acoustic foam which absorbs sound waves. The reduction in sound (attenuation) can be increased by using earplugs as well.
Sound intensity is measured in decibels (dB). The human ear can register sounds across a huge range of intensities so a linear scale is not suitable for sound measurement. The decibel scale is logarithmic where the sound intensity doubles for every 3 dB increase. An increase of 20 dB would increase the sound intensity by 100. (50 dB is 100 times louder than 30 dB)
The SNR (single number rating) is the system within the European Union to indicate the protection offered by hearing protection. The number is an average dB reduction that can be used to compare hearing protectors. The higher the SNR, the higher the level of noise attenuation provided. To determine the acoustic pressure on the ears, subtract the SNR value from the average measured noise level.
If the noise level is 108 dB and the SNR is 28 then the experienced noise level is 108 – 28 = 80 dB on average.
HML estimates the attenuation by hearing protection in 3 frequency bands. H = High , M = Medium, L = Low
Protection that reduces the sound level to below 70 dB should be avoided, since this over-protection may cause difficulties with communication. Employees may feel isolated and may remove the hearing protection risking damage to their hearing.