Optimization of vehicle horn placement based on a one-dimensional standing-wave model

Vehicle horns must satisfy sound pressure level regulations in each country. Therefore, it is essential to optimize the horn location inside the front grille of the vehicle to maximize sound transmission through the grille opening and adhere to sound pressure level regulations. This study developed a computational method to determine optimal horn locations during early stages of vehicle development to reduce the number of trials during later stages. Therefore, an analytical model based on a one-dimensional standing-wave model was established using parameters obtained in the early stages. Subsequently, spectral changes were predicted for the transfer characteristics based on the horn location (i.e., from the horn to the exterior of the front grille). The analytical model was validated by comparing computed spectral images with those obtained experimentally from sample commercial vehicles. Image correlations between the analytical model and experimental results were greater than 80%. The high correlation suggests that the analytical model sufficiently represented the sound propagation phenomena, including transmission from the front grille. Finally, the model results established the optimal horn placement, which was validated using a commercial vehicle as a case study. The placement obtained by the proposed analytical model was in good agreement with that of the commercial vehicle.