Each contour shows a sound level in decibels with the lines closest to the turbines having higher decibel levels. Developers present the sound levels as contour lines overlaid around the turbine sites. The CADNA/A tool generates predicted sound levels at various distances from the turbines.
CADNA/A is based on ISO 9613-2, the international standard developed for sound prediction. These engineers rely on the CADNA/A software tool for their models. Prior to erecting a wind facility, project owners usually engage acoustic engineers to prepare models that predict sound level increases a community can expect from an operating project at certain reference points. But given what sound experts already know about turbine noise, the time for niceties has passed.
Yes, we could use softer words to explain the situation.
