Tonkörper

Tonkörper (tone body) is a term used in acoustics and musicology to denote a physical body that can generate audible sound by mechanical vibration. The concept describes any object that, when excited, radiates sound into the surrounding air. Because the term is not as widely used as Schwingkörper or Schallquelle, many authors employ alternative German terms depending on context.

The acoustic behavior of a tonkörper is governed by its natural frequencies (eigenfrequencies), mode shapes, mass, stiffness, and damping. When excited by an energy source, the resulting vibrations produce pressure waves in the adjacent medium, with the spectrum determined by the coupling between the body and the air and by the geometry and material properties of the body. The surrounding boundary conditions influence how efficiently a tonkörper radiates sound.

In musical contexts, tonkörpers include the resonant bodies of guitars, violins, pianos, and percussion instruments, which shape timbre and loudness. In engineering contexts, they can refer to vibrating components in speakers, transducers, or modal test samples. Because the term is not standard in technical German, many sources prefer Schwingkörper, Schallkörper, or simply Schallquelle when describing vibrating bodies that produce sound.

Etymology: ton (tone) + körper (body). See also Schwingung, Resonanz, Schall, Schwingkörper.