VoMPE (Voice over MIDI Polyphonic Expression) analyzes voice input and then outputs polyphonic MIDI notes based on formant frequencies representing voice characteristics.
The process of voice production can be modeled by the vibration of the vocal cords and the resonance of the vocal tract. In this case, the voice spectrum is the product of the vibration spectrum of the vocal cords and the frequency characteristics of the vocal tract. Thus, the frequency characteristics of the vocal tract are called the spectral envelope. And the resonant frequencies of the vocal tract, i.e., the peak frequencies of the spectral envelope, are called formant frequencies. These are widely used in speech analysis, synthesis, and coding.
VoMPE estimates the spectral envelope of voice input using Linear Prediction Coefficients and then finds the formant frequencies. The spectral envelope is divided into bands and one band corresponds to one MIDI channel. VoMPE outputs MIDI notes that reflect formant frequencies whose amplitude is maximum in the band.
VoMPE is provided as a VST 3 plug-in for digital audio workstations and supports 16KHz, 44.1KHz, and 48KHz sampling rates. OS environment is 64bit Windows 11.
