ExtensionPV_NoiseSynthP and PV_PartialSynthP base these decisions on whether or not phase data across numFrames is within a given threshold.
| buffer | 
 The FFT buffer.  | 
| threshold | 
 A phase value (in radians) with which to allow values to pass through or be zeroed out.  | 
| numFrames | 
 The number of FFT frames needed to make the above decision.  | 
| initflag | 
 If 0, all bins are zeroed out while the initial is calculated. If 1, all bins pass through.  |