General conclusion
Fundamental phenomena of noise of internal combustion engines

Controlling noise from internal combustion engines is one of the most difficult tasks for automotive engineers, as the sources of noise are numerous and the phenomena complex. The work presented in this article gives an overview of the different types of noise to be dealt with and the associated methodologies (table 1 ). Over and above the methodologies and technical solutions specific to each noise, it is very important for engine acousticians to adopt a global and homogeneous approach to all the noises an engine can generate. After all, it only takes one little noise to spoil all the efforts made on the others.