Relative to Combustion Engine vehicles, electric powertrains are a blank canvas for sound. There are an increasing number of applications where sound is added to enhance the driving experience and increase pedestrian safety. In Hybrid vehicles, the combustion engine sound is not always present and must properly blend in with any additional sound added to the vehicle.
Vehicle manufacturers have an opportunity to reinforce their brand identity through the addition of the perfect, target sound. Each brand, market segment, and powertrain require unique sounds. In addition, shuttle or ride sharing applications highlight the need for added sound during other scenarios to reinforce the brand sound.
Traditional sound quality measurements and preference testing are very limited in defining the perfect sound due to the subjective nature of sound design. This paper describes an improvement over prior sound quality process development through the incorporation of several subjective input tools: Semantic Differential and Visual Mood Boards. These tools complement traditional sound quality subjective evaluation methods such as Rank Analysis and Paired Comparisons.
Several case study examples are presented to illustrate these techniques across various vehicle and powertrain types. A final design demonstrates the above process and highlights the new approach to develop a sound that meets the target brand character in the context of the NVH challenges specific to each powertrain application.