History and uses of the vocoder

The vocoder enhances many modern music tracks, especially from the 70s. It gained prominence during the peak of progressive rock and the early days of electronic music, with massive adoption by many artists. Do you know the history and intricacies of this effect that transforms voices and musical instruments?

History of the vocoder

The beginnings of the technology

The vocoder is a contraction of the words “voice” and “coder.” It was invented by an American engineer in 1939. Homer Dudley worked on improving voice transmission through audio systems, including the telephone. The purpose of the vocoder was to synthesize the human voice to facilitate its transmission.

Unfortunately, the quality of transmissions was highly lacking. The voice was extremely robotic! His device did not achieve the expected success until its integration into the SISGALY communication project launched by the U.S. military. According to Wikipedia, this early version of the vocoder, called the “voice encoder,” was one of the communication devices used during World War II. The United States and Great Britain used it to exchange coded messages between their two continents.

Subsequently, the technology offered by the vocoder was more or less abandoned. It was unsuitable for proper voice transmission for everyday use. The devices required advanced electronic engineering skills, which made them inaccessible. Additionally, a large amount of space was needed to house a single device.

The adoption of the vocoder by musicians

The vocoder made its return in the early 60s, thanks to its adoption in the electronic music world. In 1959, the German company Siemens developed a synthesizer, the Siemens Synthesizer, which incorporated a vocoder. In the late 1960s, Robert Moog, founder of the company of the same name, envisioned vocoder modules for musicians. These were used to compose the soundtrack for the film A Clockwork Orange. In 1976, the company EMS released the Studio Vocoder, the first portable vocoder. This device popularized the vocoder among many musicians, including Stevie Wonder and Kraftwerk. This encouraged manufacturers to create new vocoders like the Korg VC-10. The latter was used by a large number of musicians, including Pink Floyd on the Animals album.

How does a vocoder work?

What does a vocoder look like?

A vocoder uses two sound inputs. One comes from a microphone, and the other from an instrument. It is typically a keyboard but can be any other instrument. The vocoder should not be confused with the talk box, which operates completely differently.

Nor is the vocoder the same as Auto-Tune, which is highly valued by many artists. Auto-Tune is a computer process that uses algorithms to correct a voice’s pitch. The working principle between these three sound transformation processes is different.

Vocoder principle

A vocoder has two systems (the microphone and the instrument) that provide two inputs with two different sound signals. The vocoder’s purpose is to combine these two inputs to produce a single one. It creates a mix in which each input plays a specific role. The instrument’s signal is adapted to the microphone’s signal. The voice captured by the mic generates vocal effects applied to the instrument’s signal.

These two inputs have specific names. The carrier input is the instrument’s input. It is, in a way, the base of the mix, representing the carrier signal. Then there is the microphone input, called the modulator input, defining the modulating signal. It will apply to the carrier signal to transform it.

Let’s roughly detail the technical operation of the vocoder. The carrier input defines the timbre and pitch, to which the modulating signal is added. The final result is achieved through the use of band-pass filters that divide the two input signals into several frequency bands. Then, an analysis system inserts the modulating signal into the carrier signal. The vocoder uses the filter levels, taking into account the harmonic complexities and levels of the modulator input.

In the end, the instrument’s signal sings what is provided by the microphone input signal. Vocoders are used to generate vocals with unique sounds and rhythmic percussion from beatboxing.

Vocoder settings

A vocoder has many settings that can further modulate the signal! The vocoder can be subtle or extravagant, adding a robotic effect to the sound, as Daft Punk did on certain tracks.

Formant

This is usually a rotary knob that gives a particular timbre to the voice produced by the vocoder. Depending on the chosen parameters, it can take on a robotic voice timbre leaning towards the high end or, conversely, a darker voice with pronounced low tones. Some vocoders have several vocoding modules that transform the tone. Some are predefined; you just select them to hear the differences between each.

Quantity, level, and width of frequency bands

The precision of the vocoder’s effect application depends on the number of existing frequency bands. The more there are, the clearer and more detailed the effect! This allows for more detailed work on each passage.

Some vocoders have a predefined number of frequency bands, while others let you choose the number of bands. It’s important to note that the more bands there are, the more the computer’s processor is taxed! Applying the effect can require a lot of computing power.

It’s also possible to define the width and level of each individual frequency band.

The width of the main frequency band

This option allows you to choose the frequency range in which the vocoder operates. It enables work on a very precise frequency band.

There are many other options on vocoders. Not all of them have the same features, and not all are equally useful. There are no ideal settings to use. It all depends on what you want to achieve, your tastes, musical style, instrument, etc.

Using the vocoder in music

After World War II, the vocoder failed to find a new audience until the 1970s, when manufacturers revived vocoder technology and musicians began incorporating it into their musical projects!

The era of pioneers

Sometimes, a new device becomes widespread in a very specific style of music. The vocoder found its place in electronic music with artists like Kraftwerk or The Buggles. Then, the vocoder inspired musicians of all styles, including Frank Zappa, Electric Light Orchestra, Laurie Anderson, Alan Parsons Project, Boney M, Pink Floyd, Phil Collins, and Earth, Wind & Fire. Most progressive rock bands used it in various songs. Neil Young incorporated it into many tracks from his Trans album. Electronic music composer Jean-Michel Jarre also used it in many of his albums.

New diverse music uses

The vocoder reached its peak between the 70s and late 80s before being abandoned until the rise of Daft Punk. They brought it back to the forefront in the late 1990s with famous compositions like Robot Rock. Many artists have since integrated it into their songs, including Dr. Dre, Owl City, Beastie Boys, and Boards of Canada.

Top 5 vocoder plugins

Regardless of the vocoder plugin you want to use, you need a microphone and a MIDI controller.

Waves OVox

Waves produces many plugins for digital audio workstations. In fact, their plugins often appear in the top-used plugins! OVox has a large number of options, ranging from the vocoder, and talkbox, to arpeggio effects. It offers many possibilities to transform your tracks! It can be found online for around 40 euros, making it very accessible to many musicians!

iZotope VocalSynth 2

iZotope VocalSynth 2 is one of the most widely used VST vocoder plugins! Its interactive visualizations provide a unique experience. It features a spectral display that reacts to the modulator input. It also has several synthesis modules, including the vocoder and talkbox. Its functionalities come at a cost of about 200 €, so it’s not suitable for all budgets.

Arturia Vocoder V

For those nostalgic for the early days of the vocoder, Arturia has digitally recreated the famous 16-band vocoder made by Moog in 1979. The plugin also features an integrated analog synth, a sampler, and unique effects. It costs 149 €.

TAL-Vocoder (free)

For a low-cost option, TAL-Vocoder is one of the best since it’s free! Its interface is quite simple, making it accessible to any beginner! Sure, it doesn’t offer a large number of effects and settings, but it fulfills its role as a vocoder for small budgets.

Polyverse Manipulator

Polyverse Manipulator is an excellent plugin for vocoding voices or instruments, with various settings including a pitch shifter and a harmonics shifter. It’s a great choice among the many available plugins! It costs around 150 €.

Vocoders as physical devices

Synthesizers

As for physical devices, there are many options! For synthesizers, there are many choices. Almost all brands offer synthesizers with a vocoder: Korg, Behringer, Roland, Nord, Arturia, etc. There are numerous online comparisons showcasing dozens of synthesizers. We encourage you to read a few to make a choice. There are also alternatives for other instruments using a jack input, with two options below.

Boss VO-1

Designed for guitars, the Boss VO-1 pedal connects with a microphone and any musical instrument equipped with a jack input (electric guitar, bass, etc.). The pedal is easy to handle with a few settings accessible via rotary knobs. The result is immediate, though some time may be needed to tweak the voice/instrument mix.

Electro Harmonix V256

In the same vein as the Boss VO-1 pedal, Electro Harmonix offers its V256 pedal. It also works with a mic and any instrument with a jack output. This model is easy to use and has a few more subtleties than the Boss VO-1, with additional settings to help create unique sounds! Having never had the chance to test it, we are unsure if the price difference between the two is worth it.

From its origins in speech engineering laboratories to its adoption by musicians, the vocoder has become an iconic tool for sound creation. While it was initially developed to meet technical communication needs, it is thanks to its appropriation by artists that it has found its significance. It has established itself in electronic music and progressive rock. Its operation simplifies the generation of robotic voices, the addition of a tonal dimension to instruments, or the production of particular sound textures. Since its inception, it has captivated the most creative musicians. It remains a tool that combines innovation and artistic expression.