Abstract
This paper describes the method of designing engine sound quality at the early stage of product development. Because engine sound characteristics is determined by its fundamental structural dynamics and combustion process, engine designers need to know how the engine will sound well in advance before their designs are implemented into hardware. For this purpose, conventional sound quality evaluation tools will not be any help because they modify recorded sounds. To solve this problem, the authors created sound waveforms of combustion sound by simulating their physical generating mechanisms in a computer. The waveforms were then used in psycho-acoustic experiments using multi-media functions of personal computers. To give user-friendly environment for engine designers, graphic user interface (GUI) was development. Another method developed in this study was to use wavelet analysis and reconstruction. Intermittently occurring sound as valve noise was efficiently distinguished even under heavy background noise environments.
