Rain Dribbling On Styrofoam

This caught my attention as an unfamiliar sound, and i actually had to investigate to learn what it was. It was the raindrops hitting some styrofoam bodyboards near a swimming pool, which at times sounded almost more like a hollow "pop" than a "drip. ". In the background one can hear thunder, rain, and the humming of a pool filtration system. Recorded with an iphone 7.