Different raindrop sizes produce different sounds underwater. By listening for these different sounds, it is possible to invert the underwater sound field to obtain the drop size distribution (DSD) in the rain. An example is shown here. The underwater sound of a thunderstorm is shown at the top. The rain event consisted of a very heavy downpour (extreme convection), followed by a light drizzle (stratiform Type I), followed by a heavier stratiform rain associated with melting ice aloft (Stratiform Type II). The changes in the DSD associated with these different types of rainfall also produce changes in the sound field. The middle panel shows DSD data collected by a Joss-Waldvogel distrometer (mechanical device). The bottom panel shows the acoustic inversion for DSD. Only four drop sizes are detected acoustically, however this is sufficient to accurately measure quantities of interest, e.g. rainfall rate, reflectivity, liquid water content, median drop size, etc. [See Nystuen (2001), Nystuen (1996)]