Design optimization of a dual-shell car horn for improved sound quality based on numerical and experimental methods

The objective of this article is to describe the design method of a dual-shell car horn (DSCH) with good interior sound quality based on the boundary element method and transfer path analysis (TPA). A prediction model of the perceived sound quality was developed to determine the DSCH’s two fundamental frequencies. A boundary element model for the design of a new DSCH was also explored, and the results were applied to a drawing for the implementation of a prototype car horn. To evaluate the interior sound quality during operation of the prototype, an index for estimating the sound quality level is required. The index was developed using the slope of the spectral decay with respect to the frequency in the spectral analysis of interior sound measured inside a car. The effect of the car body on the interior sound quality was also investigated using TPA. The mounting location of the car horn on the body was changed, and the mounting bracket was modified to improve the interior sound quality. The proposed method was successfully applied to design a new DSCH with superior sound quality.