I am currently building a patch using VBAP to do surround sound for an interactive software environment. I want to create an effect where the sounds' amplitudes decrease as they "travel farther away" (in a virtual sense) from the listener (and also vice versa: amplitude increases as sounds "travel closer" to the listener). I have the virtual coordinates of the sound related to the listener all figured out, and I have VBAP working, but I just wanted to see if anyone had any advice on this subject. I'm not even really sure where to start, or if I'm even asking the right question. Thanks for any help in advance!
edit: I also think that a hi pass filter is involved, but wasn't quite sure the type of function I should be using to control that.