Tools and techniques for understanding the fundamentals of automotive sound quality

Abstract Understanding the sounds that create the most positive subjective and emotional responses for customers and, importantly, linking this knowledge to objective engineering specifications is a major challenge. This paper presents research to create the tools and techniques to achieve this. It starts with work carried out to understand the language of sound perception and a means to capture it succinctly. Two perceptual dimensions were established that enabled the positioning of current, competitor, and target vehicles in a subjective space to be determined. Early work involved the study of fixed sounds, both real and simulated, in a listening room. However, this approach has been improved by enhancing the level of context and interactivity. Perception of the sounds of on-road cars is affected by stimuli for other senses (e.g. visual and vibrational), and the fact that an assessor is also concentrating on driving. Furthermore, drivers experience a full range of vehicle sounds, rather than fixed stimuli. The development and use of interactive simulation tools are therefore introduced. They provide a more confident assessment of preferences but also allow a greater understanding of the contributing factors to these preferences, e.g. those aspects of real-world driving that are most important in forming overall impressions of vehicle sound.