THE noise environment around airports is a major cause of concern worldwide, with many local communities exposed to high levels of aircraft noise; the effective reduction of such a noise pollution represents an important challenge, both technically and financially, for the coming years. The noise generated by an aircraft in approach or takeoff configuration has two main contributions: First, the airframe noise, which results from the impinging of turbulent flows on solid structures (wings, slats, flaps and landing gears). Second, the engine noise, which results from both the jet and the turbomachinery (fan, turbine, and combustion) sound emissions. Though the airframe and engine contributions to the overall aircraft noise are roughly equal at landing, the latter is largely dominant at takeoff, due to the fact that the engine thrust is at its maximum. One big challenge for both engine builders and aircraft manufacturers is therefore to improve the acoustic discretion of engines, as well as their integration within aircraft architectures. To this end, the development of capabilities offering both a deep understanding and an accurate prediction of the physical phenomena that underlie the propulsive noise generation and propagation processes has became a priority for the Aerospace Research community.