Feasibility of a new noise prediction method using vibration speakers to verification of interior noise reduction effects

Abstract

To effectively reduce interior noise in railway vehicles, the effect of new noise-reduction measures must be pre-estimated before their implementation. We are developing a new method for interior noise prediction, using a vibration speaker to estimate the multiple-input multiple-output transfer functions from the acceleration of interior panels to the sound pressures at the evaluation points. In this paper, we verify the possibility and report on the feasibility of predicting the effect of interior noise reduction in railway vehicles when the vibrations of interior panels are reduced to improve quietness in the cabin. First, we conducted a vibration test using a vibration speaker on a Shinkansen test car to estimate the transfer functions from each interior panel to the noise evaluation point. Then, we conducted another vibration test to simulate the running condition, aiming to reproduce the interior noise. Finally, by assuming that the vibrations of the interior panels are reduced in the second vibration test, we show the feasibility of the proposed method to verify the noise-reduction effect by using it to predict the interior noise with vibration-reduction measures.