Here’s the science behind the burbling sound of water being poured
The sound’s volume depends on the smoothness of the poured stream of water

A stream of water poured from a teapot forms ridges as it falls before breaking up into individual droplets. These features affect how air bubbles form in the liquid (bottom left), explaining the variation in the sound of water poured from different heights.
Ho-Young Kim et al, APS 2023