The sound quality of systems with electric motors has become increasingly important to customer perception of vehicle quality. This paper summarizes the results of a case study of the sound quality of twelve power window systems. Paired comparisons of preference and semantic differential subjective evaluations were performed with twenty-nine test subjects. The test subjects clearly perceived differences between the power window system sounds when asked to scale the sounds using the adjective pairs of ““no whine/whine”” and “steady/fluctuating”. A regression analysis related test subject preferences to a linear combination of IS0532B band passed loudness (300-2500 Hz) and motor speed dip (% of normalized motor speed).