This paper introduces an analytical approach to investigate the stator vibration in permanent magnet synchronous motor due to variable-speed drives. The origin of vibration is studied first. Using an electromechanical impulse response, a direct link between the electrical input to the stator windings and acceleration of the stator is established. This model allows for efficient and accurate computation of the stator vibration in permanent magnet synchronous machines. Simulations and experiments are conducted to validate the claims.