Apple Shake 4 - Manual (Page 948)

948 Chapter 31 Expressions and Scripting
fnoise() and turbulence() have additional frequency factors to the noise.
Offsetting a Generator Function
To offset a function’s starting value, add a value to time.
fnoise(time,2) fnoise(time,5)
turbulence(time,2) turbulence(time,5)
cos(time) cos(time+10)