Abstract
This paper describes the effectiveness of time domain analysis for improvement engine noise. When we analyze the source of engine noise or engine vibration, we apply stationary analysis with time averaging measurement conventionary. But this analysis is difficult to exactly analyze the phenomena which changes within a short period of time. So we apply the time domain analysis which is measured with Nonstationary sound holography & Laser doppler vibrometer which made the analysis within short time priods possible, and we confirmed this analysis is effective for improvement of engine noise.
