Physical Modeling of Plucked String Instruments with Application to ...

VALIMAKIETAL.PAPERS3) Use the truncated signal as the excitation to the The analysis and synthesis results of the steel-stringstring model, acoustic guitar were similar to those of the nylon-string4) Run the string model using the parameters derived acoustic guitar. The use of the plectrum instead of thefrom the analysis, finger in the string excitation results in a different-sound-The original and the synthesized signals presented and ing residual signal, but the string model can be the samediscussed in this chapter are downloadable as sound files for both instruments.(AIFF, WAV, and MPEG-1 layer II formats) using theWorld Wide Web [46]. 4.2 MandolinThe analysis and resynthesis of the mandolin are illus-4.1 Guitars trated in Figs. 25 and 26. We notice that windowing and'From the analysis and synthesis results of the electric truncation of the residual signal have only minor effects,guitar shown in Figs. 23 and 24 it can be seen that the shortening the decay of the lowest body resonances. Thelength of the residual signal used in resynthesis can be resynthesized tone in Fig. 26(b) has been calculated usingreduced to about 50 ms without any significant loss of the first 100 ms of the residual and a single-polarizationinformation. This is due to the lack of body resonances, string model. The original mandolin signal shows a slightThe resulting sound is quite similar to that of the basic beating effect after the transient part, whereas the resynthe-KS model excited with an impulse. It is clear that in this sized tone has an exponentially decaying behavior. It is,case physical modeling principles should be extended to however, almost impossible 'to distinguish the syntheticvarious magnetic pickup combinations and amplifiers, tone from the original one by ear. Using a dual-polarization0.5 0. -i-_o. i'ii. .-1 0.05 0.1 ' 0.15 0.2 0.25 I 0.! 0.]5 012 0.25(a)(a)0._-o,-o_i i i-10 0.05 0.1 0.15 012 0.25 0.05 0.1 0.115 012 0.25Time(s)(b)Fig. 23. (a) Electric guitar tone. (b) Residual signal after in- Fig. 25. (a) Mandolin tone. (b) Residual signal after inverseverse filtering, filtering.Time(s)(b)0.5 0.50 *. 0-0.5 -0.-10 0.05 ' 0i 1 0.15 ' 0' 2 0.25 '0 0.05 0.1 0.15 0.2 0.25(a)(a)I , , , , ,-0.0'5I0 . '_/i0.250 0.05 0.1 0.15 0.2 0.25 0 0.05 0.1 O.15 0.2Time(s)(b)Fig. 24. (a) Truncated residual signal. (b) Resynthesized elec- Fig. 26. (a) Truncated residual signal. (b) Resynthesized mantricguitartone.dolintone.Time(s)(b)344 J.AudioEng.Soc.,Vol.44, No.5, 1996May