Summary

Homunculus is a free and open-source formant synthesizer implemented in JUCE under the GPL3 license. It is based on a simplified model of the human voice, using a band-limited impulse train to simulate glottal pulses and a set of resonant filters to model the shape of the vocal tract. Though it can create human-like sounds, it is capable of producing a range of other sonic textures.

Features

• Formant synthesis based on vocal tract modeling
• Performance mode with a morph slider to interpolate between formant sets
• Visualizer showing frequency response of the formant filters
• Editor mode to add, remove, and edit formant sets
• Each formant set consists of three bandpass filters with adjustable frequency, Q, and gain parameters
• Simple LFO vibrato controlled by frequency and modulation amount knobs
• Amplitude envelope with ADSR parameters for shaping sound dynamics
• Precompiled installers available for macOS and Windows

Usage

Users can switch between performance mode for live playing and morphing formants, and editor mode for detailed control over formant filter parameters. The synthesizer generates sounds by simulating glottal impulses filtered through adjustable resonant cavities.

Motivation and Development

The project was created to learn JUCE, software architecture principles, and DSP techniques such as band-limited impulse trains and filtering. Source code compilation requires JUCE and Projucer.