PARSHL: An Analysis/Synthesis Program for Non-Harmonic Sounds Based on a Sinusoidal Representation¹

Julius O. Smith III²
Xavier Serra
Center for Computer Research in Music and Acoustics (CCRMA)
Department of Music, Stanford University
Stanford, California 94305

Abstract:

This paper describes a peak-tracking spectrum analyzer, called PARSHL, which is useful for extracting additive synthesis parameters from inharmonic sounds such as the piano. PARSHL is based on the Short-Time Fourier Transform (STFT), adding features for tracking the amplitude, frequency, and phase trajectories of spectral lines from one FFT to the next. PARSHL can be thought of as an ``inharmonic phase vocoder'' which uses tracking vocoder analysis channels instead of a fixed harmonic filter bank as used in previous FFT-based vocoders.

Detailed Contents (and Navigation)

• Introduction and Overview
  • The Short-Time Fourier Transform (STFT)
  • The Phase Vocoder
  • Additive Synthesis
  • Overlap-Add Synthesis
  • PARSHL
  
  
• Outline of the Program
• Analysis Window (Step 1)
  • Choice of Hop Size
  
  
• Filling the FFT Input Buffer (Step 2)
• Peak Detection (Steps 3 and 4)
• Peak Matching (Step 5)
• Parameter Modifications (Step 6)
• Synthesis (Step 7)
• Magnitude-only Analysis/Synthesis
• Preprocessing
• Applications
• Conclusions
• Acknowledgments
• Software Listing
• Bibliography
• About this document ...