Abstract
Dynamic dampers are often used for suppressing vibrations of machines and structures. In this research, application of dynamic dampers to suppress sounds in a closed space such as cars and rooms is considered. For this purpose, effects of a dynamic damper composed of mass, spring and damping elements attached to a uniform sound tube is discussed. It is found that dynamic dampers can be used for suppressing sounds when the value of mass can be chosen small enough, contrary to the usual use of dynamic dampers. An iteration method for determining the optimal values of spring stiffness and damping coefficient is proposed.
