On this page we analyse the results we found. We will look at the differences in intensity and frequency spectra.

If we compare the intensity of the sounds of the different drops (either in the videos in results or in the graphs in process), we can see that in general the shape is the same. First there is a sound pulse generated by the impact of the droplet on the liquid surface and afther the first pulse there is an oscillating sound (which is the most clear for the largest droplet). Unfortunately we can not compare the height of the intensity of the first sound pulse. Because we were not able to fully control the position of the impact site, we needed to adjust the experimental setup such that the signal was strong enough. Thus, the distance between impact site and hydrophone was not constant such that we can not objectively compare the height of the intesity peaks. 

In this figure the frequency spectrum of the large drop. In this frequency spectrum you can see that several frequencies ranging from 0 to 500 Hz are present in the sound of this droplet. There is also a peak somewhere around 1300 Hz. Frequencies higher than 2500 Hz are not present in the sound.

In the frequency spectrum of the medium droplet you can see that there is a large peak at around 1300 Hz and that frequencies ranging from 0 to 500 Hz are also present in this sound. Any frequencies higher than 1600 Hz are not present.

In the frequency spectrum of the small droplet again frequencies ranging from 0 to 1500 Hz are present in the sound. Again there is a small peak around 1300 Hz. 

For all three droplet sizes frequencies ranging from 0 to around 1300 Hz are present. So we can't make a clear distinction between the frequency ranges of different drop sizes based on these measurements. All three drop sounds have the sound pulse of the impact in common and for the biggest droplet the oscillation after the impact is the most clear.