EXTRACTION OF PHYSICAL AND
EXPRESSIVE PARAMETERS FOR
MODEL-BASED SOUND SYNTHESIS OF THE
CLASSICAL GUITAR
Cumhur Erkut
1
, Vesa Välimäki
1
, Matti Karjalainen
1
, and Mikael Laurson
2
1
Helsinki University of Technology
Laboratory of Acoustics and Audio Signal Processing
Espoo, Finland
2
Sibelius Academy, Centre for Music Technology, Helsinki, Finland
Cumhur.Erkut@hut.fi, Vesa.Valimaki@hut.fi
Matti.Karjalainen@hut.fi, laurson@amadeus.siba.fi
http://www.acoustics.hut.fi
Abstract
The calibration of model parameters is a crucial subproblem for realistic model-based
sound synthesis. This paper describes the revision of the calibration process of a classi-
cal guitar model, and extends the parameter extraction procedure to capture information
about performance characteristics, such as the damping regimes, repeated plucks, vibrato
characteristics, different pluck styles and dynamic variations.
0 Introduction
Model-based sound synthesis of musical instruments has been an augmenting research field
in the 1990’s. String instrument models, in particular, have provided a theoretical framework
for formulation of various model-based approaches. Throughout the years, some of these ap-
proaches have gained more popularity than the others, mainly because of their computational
efficiency for real-time sound synthesis purposes and because of their good sound quality. The
path towards today’s most powerful and realistic synthesis models emerged from the extensions
by Jaffe and Smith [1] to the simple, yet efficient Karplus-Strong algorithm [2]. The extensions
emphasized the physics underlying the algorithm, and favored a modular, DSP-based formula-
tion. Later, Smith generalized these ideas to devise the theory of digital waveguide modeling
[3, 4], which is the basis of the most popular model-based sound synthesis algorithms today.
An important problem in model-based sound synthesis is the calibration of the parameter
values of the algorithms. The algorithms themselves define the type of sound generation mech-
anism, but the individual character of a specific musical instrument, such as a classical acoustic
1
© Audio Engineering Society, Inc., 2000