Timestretching in Soundbooth
Time stretching can help add cool effects to your sound by speeding up or slowing down parts of your track. I used it speed up part of my track so that my voice sounds kind of like Alvin and the Chipmunks.
To begin, highlight the area of track that you want to manipulate. Then in the top menu bar select Processes. Now select Change Pitch and Timing.
The Pitch and Timing box will open in the middle of your screen with two sliding bars appropriately named Timing and Pitch.
Sliding the Timing bar will either increase or decrease the amount of time it takes to play the selected part of your track.
Sliding left compresses the time essentially speeding up your track. Sliding right stretches out time making your track longer and slower.
Below the Timing bar is the Pitch bar. Sliding this bar left lowers the pitch. Use this to make your voice sound like the devil. Slide the bar right to raise the pitch and sound like a mouse–you’ll understand if you try it.
The important thing is that you will want to play with the balance between Pitch and Timing to get the precise sound you want at the new speed. I compressed the timing and raised the pitch to get my Alvin and the Chipmunk sound.