Many factors..... We can look at the rhythm and beat as very important and separate factors. Simply look at the importance of percussive instruments in many ancient religions. My good friend, Maroghini, a world renown percussionist, is a deeply spiritual person who participates in a lot of religious ceremonies ranging from Hindu to ancient African. The rhythm and beats of the instruments facilitate the entering into and sustaining of trance-like states. I have seen him go into trance-like states and he can play non-stop all night-long. He is seated with his legs crossed and if you pushed into him, you simply bounce off of him. Incredibly intense stuff to be a part of.... We have a small body of data on how these instruments modify brain waves.
We can look at the frequency of certain sounds (high to low) and they also interact with brain waves. The military (DARPA) is very interested in the use of sound-wave weapons and have developed some very interesting "toys."....
Add to these factors, the psychological impact that people place upon certain spiritual/religious activities......
My limited practice with the effect of sounds is that using a low frequency (bass) sound in a kiai has the effect of bottom weighting a person (person described feeling very heavy and stuck), while a high frequency (alto) sound in a kiai has the effect of rising energy (person describes becoming lighter and rising from their base). Still playing around with this stuff and trying to make sense out of it.
I follow what you are saying, and part of my focus is on how the various pitch sounds impact my feeling of center and awareness internally as well as externally. As you said, low pitch sounds lead down and a higher pitch gives a feeling of up