Glottal Effect Editor is an advanced tool for creating fully customized effect presets.
It offers direct control over the waveform on a microscopic level.
To understand this feature, first note that voice is produced by (approximately) filtering the sound coming out from glottis with a narrow, shape-varying pipe (vocal tract). At the glottis, the vocal folds open and close a few hundred times per second during phonation. If the pattern is regular and uninterrupted, a definite pitch can be heard. However, irregular patterns may produce distorted speech or growl and vocal fry effects.
In many cases the oscillation of vocal folds is modulated by some other organs or tissues so that a macro-pattern/period consisting of several (usually under 10, so less than 50 milliseconds to give an impression) fundamental periods are observed. Synthesizer V engine is able to simulate this phenomenon to some degree and the primary use of Glottal Effect Editor is to model such macro-patterns, although it can be "abused" to create vibratos and other effects.
Think of each macro-pattern as a motion picture made from a few still images. First we define two or three images with the most prominent features (i.e., key frames), and then the synthesizer will interpolate between these key frames to create the in-between states, and the interpolated pattern can be looped 20-80 times per second by synchronizing the switching of frames with the pitch.
Select the current keyframe in edit.
Note that when loop is on, the last keyframe will not be played (but jumping back to frame 0).
Position of the current keyframe within the macro-pattern.
Index of the last keyframe is the length of the macro-pattern.
Loop
Whether or not the macro-pattern should be looped.
Fade In
Fade-in duration for the effect.
Fade Out
Fade-out duration for the effect.
Filter Cutoff/Decay
A set of lowpass/highpass filters are used to mix the unmodified voice with the distorted voice. Below the cutoff frequency the unmodified voice is retained.
Low Freq Gain
Gain applied to the voice below cutoff frequency.
Open Phase
Vocal fold opening in the current keyframe.
Return Phase
Vocal fold return speed in the current keyframe.
Skewness
The balance between low and high frequency contents in the current keyframe.
