The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.

Loudness and Timbre Issues in Plucked Stringed Instruments – Analysis, Synthesis, and Design

Henri Penttinen

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Electrical and Communications Engineering for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 6th of October, 2006, at 12 o'clock noon.

Overview in PDF format (ISBN 951-22-8389-1)   [554 KB]
Dissertation is also available in print (ISBN 951-22-8385-9)


This thesis explores acoustical properties of plucked stringed instruments and proposes sound synthesis methods for plucked stringed instruments. In this thesis the investigations of the kantele, the acoustic guitar, the harpsichord, and the guqin provide analysis results, a control algorithm, and two model-based sound synthesis methods in the following way. For a modified design of the kantele, acoustical measurements and formal listening tests support the assumption of increased loudness. The investigation also provides design rules to make a plucked stringed instrument louder. An automatic plucking-point estimation algorithm is proposed for acoustic guitars with an under-saddle pickup. The automatic plucking-point estimation can be used for controlling synthesis algorithms or sound effects. Model-based sound synthesis algorithms are proposed for the harpsichord and the guqin. It was found that the harpsichord exhibits dynamic behavior, albeit limited, when the tangent is pressed down with different speeds. Moreover, the string vibrations and the body response show changes according to the playing level. Hence, the proposed synthesis algorithm is dynamic. The analysis of the guqin reveals the existence of phantom partials in the tones, differences in tones according to the termination technique, and extensive use of flageolet tones and sliding of tones. The model-based sound synthesis algorithm takes these features into account.

This thesis consists of an overview and of the following 6 publications:

  1. Penttinen, H., Erkut, C., Pölkki, J., Välimäki, V., and Karjalainen, M., Design and analysis of a modified kantele with increased loudness, Acta Acustica united with Acustica, vol. 91, pp. 261-268, 2005. Special issue on Musical Acoustics. © 2005 S. Hirzel Verlag. By permission.
  2. Penttinen, H., and Välimäki, V., A time-domain approach to estimating the plucking point of guitar tones obtained with an under-saddle pickup, Applied Acoustics, vol. 65, no. 12, pp. 1207-1220, December 2004. © 2004 Elsevier Science. By permission.
  3. Penttinen, H., Siiskonen, J., and Välimäki, V., Acoustic guitar plucking point estimation in real time, in Proceedings of the 2005 IEEE International Conference on Acoustics, Speech, and Signal Processing, vol. 3, pp. 209-212, Philadelphia, PA, USA, March 19-23, 2005. © 2005 IEEE. By permission.
  4. Välimäki, V., Penttinen, H., Knif, J., Laurson, M., and Erkut, C., Sound synthesis of the harpsichord using a computationally efficient physical model, EURASIP Journal on Applied Signal Processing, vol. 2004, no. 7, pp. 934-948, 15 June 2004. Special Issue on Model-Based Sound Synthesis.
  5. Penttinen, H., On the dynamics of the harpsichord and its synthesis, in Proceedings of the 9th International Conference on Digital Audio Effects (DAFx 2006), Montreal, Canada, September 18-20, 2006, accepted for publication. © 2006 by author.
  6. Penttinen, H., Pakarinen, J., Välimäki, V., Laurson, M., Li, H., and Leman, M., Model-based sound synthesis of the guqin, Helsinki University of Technology, Laboratory of Acoustics and Audio Signal Processing, Report 78, September 2006, Journal of the Acoustical Society of America, submitted for publication on May the 5th 2006. © 2006 by authors.

Errata of publication 3

Keywords: digital signal processing, musical acoustics, model-based sound synthesis, computer music

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© 2006 Helsinki University of Technology

Last update 2011-05-26