When it comes to para-human vocals—anything from vintage vocoders and talkbox funk to synthetic computer assistants and droid voices—I’m a big fan. That puts iZotope VocalSynth 2 squarely in my dream toolbox. The overhauled and improved vocal effect plug-in takes a comprehensive approach to creating the panoply of artificial voice sounds, whether they be as practical as auto pitch-correction and vocal harmonies or as out-there as a completely synthesized stand-in for a human voice combining elements of vocoding, talkbox, and Linear Predictive Coding (computerized voice).

VocalSynth 2 does it all with a clever and highly flexible interface consisting of five synthesis modules, a pitch and voicing engine, and seven gorgeous and configurable effects. While obviously optimized for vocals, VocalSynth 2 also applies very well to other sources such as drums, guitar, and whatever else you want to try.

You can start with the more than 100 global presets, which take you in all kinds of directions, from sci-fi creature and one-voice choir territory to the classic and familiar sounds of vintage synthetic voice effects. However, VocalSynth 2 also transcends the scope of traditional vocoders, talkboxes, and computerized voices by blending the sounds of all of them together, along with more human inspired processing.

It shows you that blend with the color-coded Anemone spectral analysis animation in the center of its window. The Anemone “breathes” in real time as the different modules work their voodoo on input audio. You can drag their level amounts up and down to hear the difference and quickly tweak other settings in the modules and effects to create your own savable presets.

VocalSynth 2’s categorizes its presets for the Auto or MIDI modes—two of the three available operation modes. A mode select page shows setup instructions for the DAW host you’re using.

The Auto mode is the simplest one. Simply drop VocalSynth 2 as an effect on an Audio track to lock your vocals (or other audio) into key with real-time pitch correction, generate harmonies or additional voices, and blend the plug-in’s ample processing from its synthesis modules and effects.

With MIDI mode, you can “play” your in-routed vocals as single notes, chords, and so on, either in real time from a MIDI controller or with written MIDI data. Here you route an audio track into a VocalSynth 2 instance on a MIDI track in order to control its pitch, similarly to a vocoder keyboard. You have the choice between polyphonic or monophonic MIDI modes, with a really fun Glide (portamento) control when monophonic.

In Sidechain mode, VocalSynth 2’s synthesis capabilities shut off. Drop a VocalSynth 2 instance on one audio track, such as a vocal, and then choose a second audio track to act like the carrier signal to the first (see Fig. 1). This lets you give the melody of an instrument track to a vocal, make any audio track “talk,” or come up with some other creative use, such as a drum track that drives a synthesizer patch.

5 Synths in 1
VocalSynth 2 has many powerful tools, but its heart truly beats through its synthesis modules, one of which—Biovox—is brand new. All of the modules, except for the pitch-shifting Polyvox, have a synthesizer section with two tunable oscillators, five oscillator types, noise, LFO, panning and low/highpass filters. There are also 21 presets for this synth section, and you can create and save your own.

iZotope bases the new Biovox on sonic qualities and vowel formation of the human vocal tract. Under its Edit tab, a Vowel pad places the emphasis on one vowel sound or blends between them. Its main-view controls adjust Clarity, the vibe of the formants, Nasal (resonance), and Breath.

A 10-band Vocoder module has volume and pan levels for each of the 10 bands. So for example you could emphasize the low, mid, or high vocoded frequencies, or send the low frequencies to the left channel with high frequencies going to the right. The Vocoder’s main controls adjust articulation, character, and the coloration from dark to bright.

For creating old-school computerized vocals, the Compuvox module feels like a more sophisticated and detailed Speak & Spell. It has a bit-crusher, three character modes, a Bats control for adding harshness, and one of my favorite features of the whole plug-in, Bytes, which elongates and rubberizes vowel sounds to various degrees.

The Talkbox module sounds quite like those famous talkboxes that hook up to a guitar or synth. It has controls for distortion and intelligibility, speaker convolution, tone, and three character modes.

Polyvox is a pitch-shifting module for adding additional voices or harmonies. Its Formant parameter affects timbre, whereas Humanize slightly alters pitch correction and timing per-voice for a less perfect/robotic sound. Character correlates formant control with pitch-shift amount (e.g. with Character at 100, a harmony voice shifted up an octave would simulate a vocal formant half the size). Even though this module has panning and the low/highpass filters—rather than the full synthesizer section—it’s still one of my favorite-sounding modules. It sweeps between low and high pitches smoothly and sounds just beautiful.

Any of these modules could act as the basis for artists dialing in their signature sound for a single vocal track or even an EP or album, but the blending of 2 to 5 modules together opens the possibilities for that signature sound to be even more distinct and original.

Center Stage
Besides the aforementioned Anemone animation that gives VocalSynth 2 its defining esthetic, the center section of the plug-in also has an X/Y pad for clicking or dragging the axis positions of two parameters. You can set the X or Y axis to almost any parameter within the modules or effects.

Under the Pitch tab, you can toggle pitch correction and set the key to any of the major or minor scales or to chromatic. You can also set optimization levels for the Low-, Mid-, or High-pitch vocals. For more robotic pitch correction, turn up the Speed and Strength controls; otherwise adjust them to taste for a more natural sound.

When in Auto mode, the Voicing tab lets you determine the tuning of VocalSynth 2’s three auto voices. Each voice can be set off an octave above, an octave below, or any number of half steps in between (or Unison). There are also level meters for each voice.

A global Output section on the right gives you a wet/dry mix, a level fader with clip-indicating meter, global panning and stereo-width controls, and a gate threshold, which helps you minimize breath, room noise or other unwanted material from VocalSynth 2’s processing.

Plug-in Pedals
When it comes to iZotope, you can generally expect outstanding effects. And that’s the case here with VocalSynth 2’s seven stompbox-style effects, which you can toggle on and off and drag and drop to rearrange their serial order into your perfect pedalboard.

The new chorus effect is one of my favorites. Its lush, creamy sound goes a step further to thickening up the already stacked layers of multi-module VocalSynth 2 patches. The new Ring Mod offers tremolo-like effects. Also, the Shred has a greater ability to create chopped, beat-repeat-style effects with an 8-step sequencer.

The remaining effects—Distort, Filter, Transform (convolution impulse responses), and Delay—all deliver detailed quality and wealth of sonic shaping options inside of simple, straightforward interfaces.

If you use VocalSynth 2 with iZotope Neutron 2, Ozone 8, O8N2, or the Music Production Suite, you’ll enjoy extra utility through iZotope’s inter-plug-in communication. For example, you can see VocalSynth 2 instances within Neutron 2’s Masking Meter and Visual Mixer to control loudness, panning, and width or within Tonal Balance Control to get visual feedback in real time and see how Vocal Synth 2 instances contribute to the mix’s overall tonal balance.

A New Generation of Voice
Almost everything VocalSynth 2 does sounds rich and resonant; either beautifully otherworldly or satisfyingly organic. There are some exceptions to that. For example, excessive use of the Biovox Breath control results in harsh and unrealistic sounds, but even that may suit a particular purpose for you.

While VocalSynth 2 is a focused and incredibly configurable creative effect that may not be a meat-and-potatoes tool for everybody, it’s hard to imagine a music producer who would not gain from it in some way, whether through basic pitch correction or vocal harmony creation. On the other hand, I predict that certain singers and producers will become absolutely obsessed with VocalSynth 2, and feel empowered to create entire compositions where all the instruments originate from the human voice or to construct casts of synthetic character voices.

In the middle ground, VocalSynth 2 should be simply a first-choice, go-to tool for all types of vocal enhancement, whether adding subtle voicings and a little extra shimmer to creating ensembles of alien machines singing. I expect it to live on DAW-template vocal tracks well into the future. 


Strengths: 5 modules cover the gamut of voice-processing. Excellent sound quality. Variable pitch correction. 3-voice harmonies. MIDI mode. Low latency. Low CPU usage.

Limitations: No favoriting option for presets.