Usually, when the noise impact assessment involves fixed plant installations (e.g. air conditioning, kitchen extracts), the noise emissions data from the plant's manufacturer would be sufficient to undertake all necessary calculations and prepare a noise assessment report. The relative location of the proposed plant installation would be compared against the location of the closest receiver and any acoustic corrections due to distance or screening would be taken into account.
Should further noise control measures be necessary, they would be included in our noise assessment report.
These may vary depending on each case, but typical mitigation measures would include acoustic enclosures, silencers, or acoustic screens.
If the noise source under investigation is an operation from an indoor environment (e.g. noise from a place of worship, pub, live music venue), we would undertake a manual noise survey during its duration. In some cases where a noise-sensitive receiver is in the immediate adjacency to an indoor noise source, we would also investigate the sound reduction properties of the building''s external building fabric, by conducting a simultaneous noise survey inside and outside the building (noise break-out measurement).
Any flanking paths can then be assessed on-site, while remedial measures to the building's shell can be proposed. These can include an upgrade of the current window system, the installation of acoustic doorsets, the setup, or calibration of a noise limiter, the installation of specific features such as lobbies, or the adoption of a robust noise-management scheme.
In cases where the noise impact assessment involves an outdoor operation, such as an outdoor concert, sports activities (moto-cross racing, clay-pigeon shooting), or outdoor industrial operations (e.g. quarries, land-fill operations), the procedure would initially include either a manual noise survey, or a long-term monitoring of noise or vibration.
All acquired data would then be analysed and its statistical trends would be compared to relevant Standards and Good Practice Documents such as BS8233, WHO Guidelines for Community Noise, Design Manual for Roads and Bridges and BS4142. Noise and vibration control measures would be proposed, while robust noise management schemes would be drafted in order to be incorporated into an overall Environmental Impact Assessment which is often necessary in this type of projects.