Abstract
In this paper a systematic and practical approach to interior noise reduction is described as applied to a front-wheel-drive passenger car, which was equipped with a four-cylinder in line engine. In the study both experimental analysis and theoretical analysis methods are used. Based on the analysis results, vibro-acoustic control measures are applied with due regard to practicality and ease of production. It was found that the noise level represented the reduction of approximate 1.5dB(A) and that sound quality is effectively improved after the structure modification. This proves that the practice of car interior noise control is successful.