3.5

144MainStage Effects
EVOC20 TrackOscillator includes an Unvoiced/Voiced detector. This unit detects
the unvoiced portions of the sound in the analysis signal and then substitutes the
corresponding portions in the synthesis signal with noise, with a mixture of noise and
synthesizer signal, or with the original signal. If the U/V Detector detects voiced parts, it
passes this information to the synthesis section, which uses the normal synthesis signal for
these portions.
A short introduction to formants
A formant is a peak in the frequency spectrum of a sound. In the context of human voices,
formants are the key component that enables humans to distinguish between different
vowel sounds—based purely on the frequency of the sounds. Formants in human speech
and singing are produced by the vocal tract, with most vowel sounds containing four or
more formants.
U/V detection parameters
• Sensitivity knob: Determine how responsive U/V detection is. Turn to the right for
higher settings, where more of the individual unvoiced portions of the input signal
are recognized. When high settings are used, the increased sensitivity to unvoiced
signals can lead to the U/V sound source being used on the majority of the input signal,
including voiced signals. Sonically, this results in a sound that resembles a radio signal
that is breaking up and contains a lot of static, or noise. (The U/V sound source is
determined by the Mode menu, as described below.)
• Mode pop-up menu: Choose the sound sources used to replace the unvoiced content of
the input signal.
• Noise: Uses noise alone for the unvoiced portions of the sound.
• N + Syn (Noise + Synthesizer): Uses noise and the synthesizer for the unvoiced
portions of the sound.
• Blend: Uses the analysis signal after it has passed through a highpass filter for the
unvoiced portions of the sound. The Sensitivity parameter has no effect when this
setting is used.