Luis I. Ortiz-Berenguer

Modeling of piano sounds using FEM simulation of soundboard vibration

Pattern‐matching methods for polyphonic transcription of piano sounds require a set of patterns that can be obtained by modeling the piano‐sound spectra. The modeling should take into account not only the string stiffness but also the effect of the soundboard impedance on the string vibration. Studies on that effect corresponding to a wide range of impedance values have previously been carried out by the authors. However, actual impedance values for real pianos must be used in the model. Although the impedance value of a few grand‐pianos have been measured by the authors, these results are not significative enough to create a model. Thus, a FEM simulation of soundboard vibration is proposed to obtain nearly‐actual impedance values. The simulation considers several cases of vibrating plates from the simplest rectangular one and increasing the similarity to real piano soundboards. The quality of the simulation is verified comparing the obtained results with either recognized theoretical results for the simp...

Approaching polyphonic transcription of piano sounds

Polyphonic transcription of piano is a challenging task due to the specific characteristics of its sound spectrum. Pattern matching method, which compares the spectrum with a set of spectral patterns, has proven to give good results, although some limitations still exist mainly when analyzing notes of the lower octaves. Present research is oriented to improve both the accuracy of the spectral patterns, especially for lower octaves, and the matching‐score calculation. The former is being carried out by developing a model of the vibration of piano. The last is aimed to decide whether a simple internal product or a more complex MSE calculation are needed and how the spectral pattern has to be modeled regarding partial levels. The model of the vibration permits calculating the partial frequencies, for which it takes into account the vibration of the stiff string and the effect of the soundboard impedance. The soundboard impedance modeling is under a deeper study using both real measurements and FEM modeling. As further work, once the model is completed, it is expected to generate the patterns by using a waveguide synthesis method. [Work supported by Spanish National Project TEC2006‐13067‐C03‐01/TCM.]