Design and Generation of a Target Sound to Achieve the Desired Sound Quality Inside a Car Cabin

This paper presents a novel method to design and generate a target interior sound to achieve the desired sound qualities of "powerfulness" and "pleasantness" inside a car cabin. A powerfulness index and pleasantness index were developed to evaluate the perceptions of interior sound based on three sound metrics: booming sensation, rumbling sensation, and the order decay ratio of the recorded interior sounds. The indexes were used for subjective evaluation of a designed target sound. An active sound design (ASD) device with an optimal weighted adaptive order filter was employed to control the magnitude and phase of the sound order related to the engine's revolution speed. A designed target sound with the desired sound quality was generated by the ASD device, which can also actively cancel out unwanted noise in a passenger car. Guidelines to design a target sound are proposed, and the way that the ASD device generates the target sound is presented. An example of the design and generation of a target sound inside a car cabin is also presented.