This technique, which is used to obtain vibration patterns and natural frequencies of surfaces, was first discovered by the German physicist Erns Chladni. It is frequently used especially in instrument making and instrument acoustics research. Because it is possible to get easy and fast results. Furthermore, the prices of the equipment required for analysis are quite reasonable compared to other modal analysis techniques.
This technique is essentially based on scattering an equal amount of dust on the surface to be measured, applying frequency through a loudspeaker held close to the surface, and evaluating the shape of these dusts during vibration. Especially at natural frequencies, shapes become very prominent. These shapes and their natural frequency values give information about the flexibility and mass distribution of the structure.
I often use Chladni patterns when calculating the elastic properties of wood materials, tuning the soundboard and braces, and in the final analysis of the finished oud.