Description:

Makes bubbly water drop sounds and looks like bubbles when displayed on an oscilloscope.

Used in Khrậng: https://www.youtube.com/watch?v=vAyCl4IHIz8

and in Planets: https://www.youtube.com/watch?v=XziuEdpVUe0&t=43s

Demonstration: https://www.youtube.com/watch?v=RL1Ugh46PoI