An electric machine assembly includes an electric machine, an inverter configured to provide pulse-width modulation characterized by a switching frequency and a controller. The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method of controlling the switching frequency to minimize a beat frequency phenomenon. Execution of the instructions by the processor causes the controller to obtain a first function (G1) and a second function (G2) based at least partially on the original pulse ratio (PR0). The original pulse ratio (PR0) is a ratio of the switching frequency and a predefined fundamental frequency. If each of a plurality of conditions are met, a new pulse ratio (PRN) is determined based at least partially on the original pulse ratio (PR0), the first function (G1) and the second function (G2).