Seat position and angle are adjusted electrically in the power seat of an automobile, and the quality of the vehicle's interior is degraded by fluctuating sound frequencies related to that seat. In this research, a sound stabilization design for the operating sound of the power seat was proposed considering the uncertainty inherent in the production assembly. Initially, the fluctuations' influence on the sound quality was evaluated by varying the frequency and the Sound Pressure Level of the operation sound, and a standard value for the sound stabilization was determined by utilizing the Taguchi method to consider the SN ratio. Next, the Taguchi method was adapted to consider a simplified model of the joint elements of the seat slide. Then, an optimal control factor for sound stabilization was specified. The sound stabilization was applied, leading to a target value for the optimal control factor that was specified in the simplified model for the joint of the power seat. Finally, that target value was optimized using the optimal control factor. We concluded that it is possible to achieve sound stabilization of power seat operation while considering the uncertainty in production assembly in this research.