Virtual Acoustic Musical Instruments:
Review of Models and Selected Research

Julius O. Smith III ( send email )
Center for Computer Research in Music and Acoustics (CCRMA)
Department of Music, Stanford University
Stanford, California 94305

Date: Oct. 19, 2005

Presentation Overheads
IEEE Workshop on Applications of Signal Processing
to Audio and Acoustics (WASPAA-05)
Oct. 16-19, 2005
http://ccrma.stanford.edu/~jos/Mohonk05/

Detailed Contents (and Navigation)

• Outline
• Voice Modeling
  • Linear Prediction (LP) Vocal Tract Model
  • Sound Example
  • ``Shiela'' Sound Examples by Perry Cook (1990)
  
  
• Recent Voice Modeling Efforts
  • Linear Prediction (LP) Vocal Tract Model
  • Klatt Derivative Glottal Wave
  • Sequential Unconstrained Minimization
  • Liljencrantz-Fant Derivative Glottal Wave Model
  • Parametrized Phonation Types
  • Sound Examples by Hui Ling Lu
  • Voice Model Estimation
  
  
• Karplus-Strong Algorithm
  • Interpretations of the Karplus-Strong Algorithm
  
  
• Digital Waveguide Models
  • Signal Scattering
  • Moving Termination: Ideal String
  • Digital Waveguide ``Equivalent Circuits''
  • Ideal Plucked String (Displacement Waves)
  • Ideal Struck String (Velocity Waves)
  
  
• Digital Waveguide Interpretation of the Karplus-Strong Algorithm
  • Equivalent System: Gain Elements Commuted
  • Computational Savings
  • Frequency-Dependent Damping
  • Simplest Frequency-Dependent Loop Filter
  • Karplus-Strong Algorithm
  
  
• Extended Karplus-Strong (EKS) Algorithm (Jaffe-Smith 1983)
  • EKS Sound Example
  • Example EKS Extension
  • String Excited Externally at One Point
  • EKS ``Pick Position'' Extension
  
  
• PLPC Cello (1982)
• Single-Reed Instruments (1986)
• Bowed Strings (1986)
• Bowed String Sound Examples
  • Cello Examples Using All Features
  • Without Dispersion
  
  
• Nonlinear ``Overdrive''
  • Soft Clipper
  • Amplifier Distortion + Amplifier Feedback
  • Sound Examples
  
  
• Commuted Synthesis of Acoustic Strings (1993)
  • Commuted Synthesis Sound Examples
  
  
• Commuted Synthesis of Linearized Violin
• Commuted Piano Synthesis (1995)
  • Synthesis of Hammer-String Interaction Pulse
  • Multiple Hammer-String Interaction Pulses
  • Complete Piano Model
  • Sound Examples
  
  
• Virtual Analog Synthesis
• Moog VCF Ladder (1966)
  • The Moog VCF (1966)
  • Moog VCF Controls
  
  
• Moog VCF Root Locus
  • Root locus as $k$ varies:
  • Root locus as one-pole pole location ($p$) varies:
  • Features of the Moog VCF
  • Discrete-Time Moog VCF (1996)
  
  
• Separation Table
  • Root Locus, Bilinear Transform Case
    (Using Separation Table)
  • Q versus Cut-Off Frequency, Bilinear Transform, With Separation Table
  • Bode plots (medium Q)
  • Notes
  • Discovery: There is a very good choice
  • Zeros at $z=0.3$ -- Q vs. Tuning
  • Zeros at $z=0.3$ -- Bode Plot
  
  
• Farewell Bob Moog--and Thank You!
• Online Resources
• About this document ...