How to Use a Vocoder on Audacity
By Seamus Islwyn
A vocoder combines a recording of a human voice with a synthesized waveform to produce a robot-like effect. The Audacity free, open-source audio editing program includes a vocoder plug-in that you can use to produce this effect. Audacity's vocoder requires you to create a stereo waveform with the vocal on the left channel and the synthesized sound on the right. The vocoder then modulates the left-hand channel with the right-hand one.
Launch Audacity. Open the "File" menu and hover the mouse over "Import." Click "Audio."
Navigate to the vocal recording to which you want to apply the Audacity vocoder. Double-click the file to load it into Audacity. Click "OK" if Audacity asks you to confirm the import method.
Open the "Tracks" menu. Click "Stereo Track to Mono" to convert the imported audio to a mono track. Open the "Tracks" menu again, hover the mouse over "Add New" and click "Audio Track." Audacity will create a new mono audio track underneath the vocal.
Open the "Generate" menu and select "Tone." Set the "Waveform" to "Sawtooth." Click "OK." Audacity will generate a carrier waveform for the vocoder to use.
Click the down arrow next to the name of the vocal in the upper-left corner of the Audacity mixer window. Click "Make Stereo Track" to join the vocal and the generated tone.
Open the "Effect" menu and scroll down to the bottom of the list of effects. Click "Vocoder" to open the vocoder plug-in.
Adjust the "Number of Vocoder Bands" slider in the vocoder plug-in window as desired. The more bands you use, the smoother the vocal will sound; however, a high number of bands will also greatly increase the effect's processing time.
Click "OK" to apply the vocoder effect. Click "Play" to listen to the vocoded vocal.
- If the vocoder effect doesn't show up in the Effect menu, upgrade to the latest version of Audacity.
- Try using different waveform types and frequencies to produce different vocoder effects.
Seamus Islwyn has been writing for radio, print and online publications since 2003, covering subjects from independent Canadian music to automobile smuggling in the Balkans. His work has appeared in the "Tirana Times" in Albania, and he also composes and produces electronic music. Islwyn holds a Bachelor of Arts in English from McGill University and a certificate in radio broadcasting from Humber College.