ESTIMATING PARAMETERS FROM AUDIO FOR AN EG+LFO MODEL OF PITCH ENVELOPES

Envelope generator (EG) and Low Frequency Oscillator (LFO)pa- rameters give a compact representation of audio pitch envelopes. By estimating these parameters from audio per-note, they could be used as part of an audio coding scheme. Recordings of various instruments and articulations were examined, and pitch envelopes found. Using an evolutionary algorithm, EG and LFO parame- ters for the envelopes were estimated. The resulting estimated en- velopes are compared to both the original envelope, and to a fixed- pitch estimate. Envelopes estimated using EG+LFO can closely represent the envelope from the original audio and provide a more accurate estimate than the mean pitch.