8
Table Of Contents
- Logic Express 8 Instruments and Effects
- Contents
- Introduction to the Logic Express Plugins
- Amp Modeling
- Delay
- Distortion
- Dynamics
- EQ
- Filter
- Imaging
- Metering
- Modulation
- Pitch
- Reverb
- Specialized
- Utility
- EVOC 20 PolySynth
- EFM1
- ES E
- ES M
- ES P
- ES1
- ES2
- The ES2 Parameters
- Tutorials
- Sound Workshop
- Sound Design From Scratch, Filter Settings, Digiwaves
- Three Detuned Sawtooth Oscillators and Unison Mode
- Extremely Detuned Monophonic Analog Sounds, Effects
- Clean Bass Settings With One Oscillator Only
- Distorted Analog Basses
- FM Intensity and Frequency
- Controlling FM Intensity by an Envelope and FM Scaling
- FM With Drive and Filter-FM
- FM With Digiwaves
- FM With Wavetables
- Distorted FM in Monophonic Unison
- FM With Unusual Spectra
- Slow and Fast Pulse Width Modulations With Oscillator 2
- Pulse Width Modulation With Two Oscillators, PWM Strings
- Ring Modulation
- Oscillator Synchronization
- First Steps in Vector Synthesis
- Vector Synthesis—XY Pad
- Vector Synthesis Loops
- Bass Drum With Self-Oscillating Filter and Vector Envelope
- Percussive Synthesizers and Basses With Two Filter Decay Phases
- Templates for the ES2
- Sound Workshop
- EXS24 mkII
- Learning About Sampler Instruments
- Loading Sampler Instruments
- Working With Sampler Instrument Settings
- Managing Sampler Instruments
- Searching for Sampler Instruments
- Importing Sampler Instruments
- Parameters Window
- The Instrument Editor
- Setting Sampler Preferences
- Configuring Virtual Memory
- Using the VSL Performance Tool
- External Instrument
- Klopfgeist
- Ultrabeat
- GarageBand Instruments
- Synthesizer Basics
- Glossary
- Index
Chapter 14 EVOC 20 PolySynth 165
Unvoiced/Voiced (U/V) Detection
Human speech consists of a series of voiced sounds (tonal sounds) and unvoiced
sounds (noisy sounds). The main distinction between voiced and unvoiced sounds is
that voiced sounds are produced by an oscillation of the vocal cords, while unvoiced
sounds are produced by blocking and restricting the air flow with lips, tongue, palate,
throat, and larynx.
Should speech containing voiced and unvoiced sounds be used as a vocoder’s analysis
signal, but the synthesis engine doesn’t differentiate between voiced and unvoiced
sounds, the result will sound rather toothless. To avoid this, the synthesis section of the
vocoder must produce different sounds for the voiced and unvoiced parts of the signal.
For that reason, the EVOC 20 PolySynth 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, a mixture of Noise +
Synth, or with the original signal (Blend). 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.
∏ Tip: Speech intelligibility is highly dependent on high frequency content, as human
hearing is reliant on these high frequencies to determine syllables within words. Bear
this fact in mind when using the EVOC 20 PolySynth, and take care with filter frequency
settings in the Synthesis and Formant Filter sections. To aid intelligibility, it may be
worthwhile using equalization to boost particular frequencies in the mid to high
frequency range, before processing the signal with the EVOC 20 PolySynth. Please see
the “Tips for Better Speech Intelligibility” on page 169 for further information.