This tool can be used to assess the likely effect of industrial and commercial sound upon premises used for residential purposes, as well as people who might be outside or inside such a dwelling.
The tool is based upon and uses calculations from BS4142 to assess whether or not a specific sound level will have an adverse impact in the immediate area.
BS4142 is a British Standard that describes methods for rating and assessing sound of an industrial and/or commercial nature as well as ambient, background and residual sounds for the purposes of investigation complaints, assessing sound from proposed, new, modified or additional sources of sound and assessing sound at proposed new dwellings or premises used for residential purposes (The British Standards Institution 2014).
Figure: Sound level variation of a factory with time
In order to use the tool the user will need to have previously measured or calculated the ‘Ambient Sound Level’, ‘Residual Sound Level’ and ‘Background Sound Level’. The values of these should be entered into the appropriate boxes in the calculation section below.
‘Reference Time Interval’ and ‘Measurement Time interval’ then need to be considered along with the specific sound characteristics to calculate the ‘Specific Sound Level’.
‘Acoustic Feature Correction’ can then be carried out depending on whether or not acoustic features are present. The user will need to select the appropriate feature correction from the drop down menu whereby the ‘Rating Level’ will be computed.
The ‘Excess of rating over background sound level’ is then automatically calculated and the ‘Results of Assessment’ are given depending on the sum of this value.