Environmental Noise Monitoring to BS 4142:2014
There is often a need for Environmental Noise Monitoring to BS 4142:2014 when industry is next to housing. It can affect the quality of life of the people subjected to it.
Environmental Noise from industry can also be a problem for Business. Noise Monitoring can be useful for many reasons. For Business, it can be:
- In response to complaints.
- Where there is a need to predict future noise. This allows us to estimate the steps that will be required to reduce the problem.
- When a site’s licensing hours are under review.
- Or when otherwise required by planning conditions
What does Environmental Noise Monitoring to BS 4142:2014 involve?
Our Environmental Noise Monitoring Assessments follow BS 4142:2014 – Methods for rating and assessing industrial and commercial sound. So, the process involves taking measurements and working out a number of different figures. Such as:
The Ambient sound.
This is the total sound coming from many sources at the test point. Because of this, the ambient sound includes the sound produced from the process of concern, known as the specific sound.
Following this we measure the Residual sound. The residual sound is the sound that’s left at the assessment location when the specific sound is not active. As a result, it does not add to the ambient sound.
Background sound level, LA90, T. This is the sound pressure level, at the test point, that the residual sound is above for 90% of the time.
Specific Sound Level – Ls. This is the Environmental Noise to BS 4142:2014 term for the continuous A-weighted sound pressure level that the sound source produces at the test point. Sometimes it is not possible to work out the specific sound level by measurement of the ambient and residual sound level alone. For example because the difference between them is too low. In this case, we work out the specific sound level from each of the separate sources.
Acoustic Feature Correction. This is the correction to the specific sound level because of its nature. It usually increases the impact of the noise over the basic comparison between the specific sound and the background sound.
Rating Level. The Acoustic Feature Correction added to the Specific Sound gives the Rating Level.
Excess of Rating over Background Sound Level. The Rating Level minus the Background Sound Level gives the excess of rating over background Sound Level.
Environmental Noise Monitoring to BS 4142:2014 Results
The result of the exercise gives a figure called the Excess of Rating over Background Sound Level (dB). BS 4142:2014 states that the larger this is, the larger the problem is likely to be. The standard rates the results as below:
- A difference of greater than 10 dB is likely to be an indicator of a significant adverse impact.
- A difference of about 5 dB is likely to be an indication of an adverse impact.
- The lower the rating level is, the less likely it is that will be an adverse impact.
The Environmental Noise Monitoring Report will consider the impact on people in the nearby Area. It is assessed using the guidance given in BS 8233:2014 – Guidance on sound insulation and noise reduction for buildings. This allows us to work out what the indoor ambient noise levels will be. We look at these results for both day time and night time and with the windows closed or open. Since environmental noise can also be a problem outdoors, the environmental noise assessment will also work out the impact of noise in areas such as gardens.