To provide an apparatus capable of reducing intrior noises by reducing vibrational energy of solid born sound generated from a running gear without changing a mechanism and a structure of power transmission of the running gear, or an attenuation factor of an elastic material.

A coupling portion of a car body coupled to a running gear is provided with a dynamic damper including a rubber pad and a damping mass 14 in order to reduce an amplitude ratio of resonance of solid born sound generated from the running gear. Alternatively, the coupling portion of the vehicle body coupled to the running gear is provided with a vibration exciter 17 having an acceleration sensor 16 and the damping mass 14. Moreover, a controller 22 is provided for operating excitation force necessary for reducing vibrational energy of the solid born sound generated from the running gear in accordance with vibrational acceleration from the acceleration sensor 16 so as to command the vibration exciter 17.