Different sound wave frequencies have differing effects on our neurological system. It is fun to test this out.
Plus the basic vibrations that stimulate physical elements of the body through resonance as a means to identify and feel those elements working - and to energize them. When utilizing the physical elements at their resonance frequencies the efficiency at which they can 'channel' energy is greatly enhanced. Also fun to play with while maintaining a connection in a static position and run through a range of frequencies until finding the ones that resonate with that connection. Thankfully, one can do this in solo practice while no one is looking as it does look quite silly.
I never heard anyone explain it like the above as I just stumbled upon it myself ... could be a rabbit hole.