What it does
One Channel Frequency Vocoder built from scratch
Illustrates how to construct a one channel "vocoder" effect from basic elements. They key components are the Spectral Peak Detector and the Controllable Combo Oscillator. The Spectral Peak Detector measures (approximately) the amplitude and frequency of the dominant spectral component in the audio track ("drums.wav"). In this example, only the frequency measurement (the first output of the Spectral Peak Detector) is used (the second output -- the rms amplitude measurement -- is unconnected). The frequency measurement (in Hz) is used to drive the Controllable Combo Oscillator which produces a sequence of synthesised tones derived from the time-varying spectrum of the drum track. By mixing the synthesised signal with the original track, the desired effect is achieved, namely, the creation of bizarre spectral highlights on top of the drums. The Random Telegraph Panner enhances the overall effect.
Try experimenting with all settings of all components in order to appreciate the wide range of interesting effects achievable from this simple combination.