The course starts with making the students aware of the existence of international regulations that limit noise emissions from aircraft. Noise is described really as unwanted sound which to some level always exists due to interactions of the system elements or the system itself with the working fluid environment. Therefore, the course continues with the defition of sound, the basic equations that govern its propagation, concepts of frequency, amplitude, sound pressure levels, frequency-time domain relations. It is then shown that the basic equation governing sound propagation can be obtained from the fundamental flow equations. Inhomogenous wave equation is also introduced with analytical solutions in free-space. Lighthill's theory of sound generation is described with its application to estimate the scales of sound based on the relevant parameters of the source region. The 8th-power law is obtained that explains the success of reducing the jet noise over the years by introduction of turbofan engines. Effects of source convection is discussed. A similar analogy for sound generation by moving bodies is also given in relation to moving helicopter blades, and the sources of sound on such a configuration are explained. Interaction of rotor-stator blades on turbomachines causes tonal noise and its physics is discussed. The mathematical relation that describes the interaction mechanism is given. The sound propagation through constant cross-sectional ducts is discussed that leads to understanding of propagation and radiation mechanisms for generated sound internally in engines. The cut-off ratio is described. By advent of very capable computers as well as advanced numerical algorithms noise generation and propagation problems started being treated computationally. The area that deals with this is called computational aeroacoustics. Important points one must be aware of in computational aeroacoustics are also discussed. The commonly used Kirchhoff's method for extrapolating nearfield acoustic solution to far-field microphone locations is derived for quiescent medium, and points about which one must be careful in applications are explained. Also the numerical errors associated with numerical algorithms are described and principles of good algorith design are given. Analytical treatment of jet noise radiation from literature is discussed briefly with emphasis on understanding of the generation mechanisms and flight effects on radiation.