Abstract: A method is described for attenuating the amplitudes of multiple harmonic noise components contained within noise generated by an internal combustion engine, based upon the rotation of the engine in its operating cycle. A signal representing selected multiple harmonic noise components is generated from a table of values, based upon the engine rotation. This signal is adaptively filtered to produce a canceling waveform, which is superimposed with the engine noise to attenuate the selected multiple noise harmonics. The method is useful for selecting and attenuating dominant noise harmonics produced at different engine speeds or by different types of engines, and the dominant harmonics of different forms of noise produced by the same engine.