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In this paper a study of the magnetic noise in three-phase one and two-speed cage rotor, totally enclosed, externally cooled induction motors is presented. Investigations include two-speed three-phase induction motors with Dahlander winding connection or separate windings, with rated speeds of 3000/1500 rpm, 1500/750 rpm, 1500/1000 rpm. The investigated motors (manufactured by SC Electroprecizia SA) were placed in a semi-anechoic chamber in order to determine the noise versus frequency characteristics (spectrograms). The paper is based on results and conclusions obtained after analyzing these spectrograms. The importance of the pressure applied by the stacking of the stator laminations for the level of the magnetic noise is also presented.