Maunder, M., Grant, P., and Mawdsley, D., "System for Realistic Augmentation of Sporty Engine Sound Quality," SAE Technical Paper 2016-01-1781, 2016, doi:10.4271/2016-01-1781.
Engine sound quality is a key attribute for sporty cars - it powerfully conveys the brand image to the driver/passengers and onlookers, and provides driver involvement by giving instant feedback about how a car is operating. Providing this has become more difficult with tighter pass-by noise regulations and the near-universal adoption of turbocharging.In the last two decades, sporty sound inside the cabin has been regained using intake sound generator systems that transfer sound more directly to the vehicle interior. The high cost of these systems is more recently driving a move towards electronic Active Sound Design with systems delivering synthetic sound through loudspeakers. However, the purist sports car market perceives this approach to be fake or artificial.An alternative approach is provided by a system for Realistic Augmented Sound by Ricardo (RAS-R) that offers a choice of two realistic engine sound sources. The first is a physical model using Ricardo WAVE-RT software that accurately reproduces engine sounds from real time simulation. The second is an intake manifold sensor that uses dynamic pressure fluctuations as a source for real engine sound. The sound level instantaneously reacts to the car’s speed and load, while additional processing further controls the sound quality. Surround sound playback is through a loudspeaker system.Harmoniously blended into the natural sound field, the augmented sound powerfully enriches the dynamic driving experience and is highly adjustable to match the brand image. The augmented sound is genuine, natural and honest, a step forward in acoustic realism when using WAVE-RT synthesis, and unquestionably authentic when using the intake manifold pressure sensor.