To investigate the differences in generated noise between simulated and natural rainfall the following was done: • A small-scale rain noise facility to ISO 10140-1:2016 and ISO 10140-5:2014 was constructed. The facility was commissioned with the characteristic parameters of drop diameter, drop velocity and rainfall rate being measured. These parameters agreed well with ISO 10140-5:2014. • Sound Intensity measurements were made on a 1200 x 1200 x 0.55 mm flat steel sample mimicking normal roof construction with guidance from ISO 15186-1:2000 and ISO 9614-1:1993. Vibration measurements were conducted too.

Both sound intensity and vibration showed a general broadband response with no significant difference between the simulated and random drop sources. Overall, this project has shown that there is no significant difference in the generated noise between simulated (static) incidence of drops and random incidence of drops on roofs.