IAR and modal analysis in stringed traditional musical instruments

Modal analysis is often considered quite important to describe the physics of Musical Instruments and their sound radiation. Nevertheless, several authors as Wogram, Suzuki and Giordano did not find strong correlation with modal analysis, and therefore further researches were requested. A new acoustical parameter, called Intensity of Acoustic Radiation (IAR), was recently defined, and resulted very well related with mechanical vibration of sound source, being able to quantify the sound efficiency of musical Instruments. IAR relates mechanical vibration of surface (e.g. soundboards) and sound generation of the musical Instruments. In this paper three traditional persian musical instruments: the thar, the si-thar and the santoor, were studied. In all cases modal analysis was conducted and modal pattern obtained. The IAR was also experimentally measured on them. Finally, IAR and MA were compared and the comparison pointed out the relevance of some modal patterns in the sound generation of these musical instruments.