Air intake noise
Fundamental phenomena of noise of internal combustion engines

We need to distinguish between two types of noise: intake noise, caused by the pulsating flow of air entering through the intake port, and radiated noise, caused by the intake system components, which vibrate under the effect of the pressure pulsations of the air stream circulating inside them, or under the effect of engine vibrations (air filter, rubber or plastic ducts).

This section describes the physical phenomena and technical solutions for intake manifold noise, since this type of noise is more prevalent in today's automobiles than radiated intake system noise.