Vocal Synthesizer Workshop: Modeling the Human Vocal Tract

Vocal Synthesizer Workshop

Make Something that Talks!

This 2 hour, advanced workshop was run at MoogFest, featuring the littleBits Synth Kits and logic modules. The goal of the workshop was to create a modular synthesizer that models the human vocal tract by producing vowel and consonant sounds, or phonemes.

Ideal for 20-30 people who are knowledgeable and interested in music, synthesizers and electronics. We suggest splitting the participants into groups of 2-4 people, depending on the amount of supplies available and user abilities. Download the attached pdf and provide a printout to each group.

This workshop is best run with at least 2 facilitators: 1 for the workshop/lecture overview and 1 for helping participants with the builds.

littleBits modules needed per group:
– 1 power module (battery + cable)
– 2 oscillators
– 3 micro sequencers
– 3 filters
– 1 random
– 2 envelopes
– 3 splits
– 2 mix
– 1 speaker
– 2 number bits
– 1 wire
– 1 dimmer
– 2 LED
– 2 forks
– 1 inverter
– 1 XOR
– 1 NOR

Duration: 2 hours

College/University (age 18+)
High School (ages 14-17)


Makerspace Workshops

dimmer (1)
led (2)
power (1)
fork (2)
inverter (1)
oscillator (2)
random (1)
micro sequencer (3)
envelope (2)
filter (3)
mix (2)
split (3)
synth speaker (1)
XOR (1)
NOR (1)
number (2)
battery + cable (1)
wire (1)


STEP 1 : Introduce littleBits

Vocal Synthesizer Workshop1

Provide a brief introduction to littleBits and show a demo on how the different color-coded, modular electronics function.

STEP 2 : Lecture Overview and Introductory Synth Circuits

Vocal Synthesizer Workshop2

Using the attached presentation, the workshop lead provides a background on vocal synthesis and how we can use electronics to mimic pitch, timing and formant control signals to produce vowels and consonants. It’s helpful to demonstrate the different sounds using your mouth and vocal cords.

STEP 3 : Build the Synth Circuits

Vocal Synthesizer Workshop3

Participants can begin experimenting with the basic circuits required to build the vocal synthesizer. See pages 11 to 14 for detailed information on how to construct and modify the circuits.

Helpful Tips:
– % is controlled by turning the knobs on the modules clockwise; this is based on values 0 to 100.
– The three filters in the vocal synth must be tuned to the same note. You can do this by ear, as described on page 11, or by using a guitar tuner or equivalent. The exact pitch is not important, as long as all the filters are tuned to the same pitch, and that pitch is generally close based on the knob positions described.
– As you build each section of the synth and be sure to tune and test it (instructor can provide guidance).

STEP 4 : Create the Vocal Synthesizer

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Once you have completed the previous steps, your group is ready to create the vocal synthesizer. Refer to pages 15-16 for an explanation on how to construct and tune the instrument. Pages 17-21 describe how to produce different words, including ‘cookie’, ‘barbecue’, ‘autobahn’ and ‘robot’.

Helpful Tips:
– Practice makes perfect! Small variations in your setup and controls can effect the sound.
– The number modules show the filter read outs (we use % for our notation, but be sure to have the module on the ‘value’ setting).
– Refer to page 22 for control references for producing different vowel and consonant sounds.
– If you are looking to produce male or female sounding ‘voices’, you’ll need to tweak your controls a bit differently.

STEP 5 : Extension: Adding Arduino

Vocal Synthesizer Workshop5

For an additional challenge, refer to pages 24-26 for ways to incorporate the Arduino at Heart Module into your synthesizer to improve the functionality.