Abstract
The quantization procedure for low-frequency modes in a plasma has been generalized to include dust-Coulomb waves (DCWs) which are driven by the grain charge oscillations in a dusty plasma. We thus introduce the concept of "chargeon", the elementary excitation of the ultra low-frequency electrostatic fields in a dusty plasma, which are mainly supported by the grain charge oscillations. Their characteristic features are similar to the usual phonons, but they correspond to very different physical properties of the medium.