Noise can cause irreversible hearing damage, but failure to use hearing protection or ear defenders can also cause a range of other health problems such as cardiovascular problems, high blood pressure, muscle tension and stress.
Hearing damage accounts for half of all occupational injury cases reported to the Norwegian Labour Inspection Authority. Hearing loss caused by noise in the workplace is also the most common occupational injury on a European level. It is caused by a failure to use ear defenders and hearing protection in the workplace, or by incorrect use of this equipment.
Distracting noise can also be a safety risk as it can make it hard to hear and understand important signals or other communication at work.
The need for hearing protection and ear defenders must be assessed
The risk of hearing damage depends on the noise level, the frequency and duration of the noise exposure. Employers have an obligation to protect employees from noise-related health hazards, and for performing the required noise level readings to assess both average noise levels and impulse noise generated by, for example, shots and impact. This allows them to assess the need for correct and necessary use of hearing protection and ear defenders.
Types of hearing protection and ear defenders
The most effective way of reducing noise is always to eliminate the source of the noise altogether. Where this is not possible, we offer a wide range of hearing protection and ear defenders capable of ensuring that the recommended noise level is maintained. These options include foam earplugs, banded earplugs, moulded reusable earplugs, passive ear defenders and electronic ear defenders, all by market-leading manufacturers. Our hearing protection and ear defenders can be made compatible with radio communication, ambient noise and audio communications.
Protective measures, including hearing protection or ear defenders, must be put in place when the average noise level over an eight-hour period is between 80 and 85 dB. The upper limit for impulse noise is 130 dB.
Each ear defender and hearing protector is given a Single Number Rating (SNR), indicating the equipment’s noise attenuating ability in dB. The SNR method provides an average protection factor measured across the entire frequency spectrum. However, the method does not take into account variations in acoustic pressure between different frequency areas. Ear defenders or hearing protection with an SNR value of 24 will reduce a known average noise level of 97 dB over the course of eight hours to 73 dB (97 dB - 24 dB = 73 dB). The HML (High, Medium, Low) method provides an average protection factor at the different frequencies. In order for it to be possible to use this method, the acoustic pressure in the different frequency areas must be measured.
- High: Above 1,000 Hz
- Medium: 500-2,000 Hz
- Low: Below 500 Hz
The SNR and HML values can be found in the reduction overview that accompanies hearing protection and ear defenders.
Choosing hearing protection and ear defenders
The best hearing protection is that which is used 100% of the time when in a noise zone. The level of protection offered by hearing protection and ear defenders is significantly reduced when these are removed for short periods of time. We recommend using hearing protection or ear defenders which bring the noise level down to between 70 and 80 dB. Overprotection can prevent the user from being able to hear important communication or warning signals.