As advanced technologies are deployed to improve fuel economy, such as variable cylinder activation management and lower RPM torque adjustment, the in-cabin noise produced by the car can be harsh. Furthermore, electrification of the vehicle makes them eerily quiet. As such acoustics in the vehicle are now being designed to address both poles of requirements: decrease unwanted cabin noise and create signature engine sounds internal and external to the vehicle.
QNX® Active Sound Design (ASD) reduces unwanted noise, augments desirable noise and generates new sounds both internal to the vehicle and externally as warnings to pedestrians. ASD consists of multiple software components that integrate seamlessly together with other acoustic functional modules within the QNX Acoustic Management Platform.
ASD components include Active Noise Control (ANC), Engine Sound Enhancement (ESE) and the Acoustic Vehicle Alert System (AVAS) compliant, eXternal Pedestrian Alert (XPA).
ANC provides a high-performance software solution that allows harmonic order reduction for sounds produced by engines in passenger vehicles. By allowing automotive system designers to leverage existing audio and infotainment hardware, the all software QNX ANC library provides cost reductions versus existing hardware ANC solutions – while simultaneously increasing performance by up to 50% and providing more design flexibility.
ESE provides a comprehensive tool and runtime library to help automakers and Tier 1s create or maintain signature engine sounds and enhance the appeal of their vehicles. The technology helps enhance naturally transmitted engine sounds by playing synthesized sounds synchronized to the vehicle's realtime data, including RPM and engine load, over the vehicle's speakers.
XPA provides audio alerts external to the vehicle and is AVAS compliant. This flexible software solution provides a coordinated warning sound generation synchronized with the existing acoustic record/playback to ensure that latency and accuracy requirements are met.
Various types of enhanced drive-train technologies, such as variable cylinder activation management and lower RPM torque adjustment, help improve fuel efficiency but come at the cost of increased cabin noise. An engine that deactivates 3 of its 6 cylinders to reduce fuel consumption sounds noticeably different from when it's operating on all 6 cylinders. On the other hand a gasoline-electric hybrid vehicle is very quiet.