You can do this in the timeline, but it only works to a certain extent. I’ve found its better with speeding up a sound rather than slowing it down, so make sure the original is the slowest you want it to be.
-Firstly, add the pitch shifter effect to the channel you want to affect.
-Secondly, check the image and choose one of the “pitch effect” column values and put that into the Pitch Shifter’s “pitch” knob.
-Then, on the timeline clip itself, change the clips pitch value to be the opposite value than the "pitch effect you put on the pitch shifter’s channel.
-NOW, Automate the values on whatever parameter you would like to have the unaffected value at one end , and your new sped up version at the other end.
Here’s an image of the pitch values that correlates to whole pitch changes. (Click it to see the proper size iIguess)
The actual formula for working out the pitch effect change is …=2^(PITCH SHIFT AMOUNT/12)
Hope this helps.