how does throttle work

[djashjones]

I'm trying to write a program that simulates a throttle from a merlin. Then im going to port it into a embedded board to be fitted in a 120 size mustang.

I have 5 wav files, idle & 4 at different rpm speeds. what do i need to do to make it sounds linear i.e. as i move the trackbar (throttle) the engines goes from idle to full bore?