Volume 119, Issue 3, March 2006
Index of content:
- MUSIC AND MUSICAL INSTRUMENTS 
119(2006); http://dx.doi.org/10.1121/1.2164989View Description Hide Description
Electronic speckle patterninterferometry has been used to study the deflection shapes of a pianosoundboard. A design for an interferometer that can image such an unstable object is introduced, and interferograms of a pianosoundboard obtained using this interferometer are presented. Deflection shapes are analyzed and compared to a finite-element model, and it is shown that the force the strings exert on the soundboard is important in determining the mode shapes and resonant frequencies. Measurements of resonance frequencies and driving-point impedance made using the interferometer are also presented.
Contribution to harmonic balance calculations of self-sustained periodic oscillations with focus on single-reed instruments119(2006); http://dx.doi.org/10.1121/1.2166602View Description Hide Description
The harmonic balance method (HBM) was originally developed for finding periodic solutions of electronical and mechanical systems under a periodic force, but has been adapted to self-sustained musical instruments. Unlike time-domain methods, this frequency-domain method does not capture transients and so is not adapted for sound synthesis. However, its independence of time makes it very useful for studying any periodic solution, whether stable or unstable, without care of particular initial conditions in time. A computer program for solving general problems involving nonlinearly coupled exciter and resonator,HARMBAL, has been developed based on the HBM. The method as well as convergence improvements and continuation facilities are thoroughly presented and discussed in the present paper. Applications of the method are demonstrated, especially on problems with severe difficulties of convergence: the Helmholtz motion (square signals) of single-reed instruments when no losses are taken into account, the reed being modeled as a simple spring.
119(2006); http://dx.doi.org/10.1121/1.2168549View Description Hide Description
This paper examines the differences between three Croatian folk singing styles, namely klapa, ojkanje, and tarankanje. In order to factor out singer-specific properties, each of the styles was performed by the same 12 professional male singers. The 36 performances were analyzed with a long-term average spectrum (LTAS) method from which direct effects of the pitch distribution were removed. After factoring out each singer’s average, the 36 pitch-corrected LTAS contours were reduced to a two-dimensional representation in two ways: (1) a principal-component analysis and (2) a graphical plot of spectral slope versus speaker’s formant strength. Both ways clearly separate the three styles. The spectrum of the klapa style turns out to be similar to that of speech. The ojkanje style is extremely loud and shows two spectral peaks: a sharp one tuned at twice the fundamental frequency and appropriate for long-distance communication on mountain slopes, and a broad one around , reminiscent of a speaker’s formant. The tarankanje style has a very flat spectrum implemented by vocal pressedness and nasality, which is appropriate for blending into or imitating the timbralcharacteristics of the sopile folk instrument.