Building (sound) character into cars

Tina Jeffrey

Modern engines are overachievers when it comes to fuel efficiency — but they often score a C minus in the sound department. Introducing a solution that can make a subtle but effective difference.

Car engines don’t sound like they used to. Correction: They don’t sound as good as they used to. And for that, you can blame modern fuel-saving techniques, such as the practice of deactivating cylinders when engine load is light. Still, if you’re an automaker, delivering an optimal engine sound is critical to ensuring a satisfying user experience. To address this need, we’ve released QNX Acoustics for Engine Sound Enhancement (ESE), a complementary technology to our solution for active noise control.

The why

We first demonstrated our ESE technology at 2014 CES
in the QNX technology concept car for acoustics.

Many people assume, erroneously, that ESE is about giving cars an outsized sonic personality — such as making a Smart ForTwo snarl like an SRT Hellcat. While that is certainly possible, most automakers will use ESE to augment engine sounds in subtle but effective ways that bolster the emotional connection between car and driver — just like engine sounds did in the past. It boils down to creating a compelling acoustic experience for drivers and passengers alike.

ESE isn’t new. Traditionally, automakers have used mechanical solutions that modify the design of the exhaust system or intake pipes to differentiate the sound of their vehicles. Today, automakers are shifting to software-based ESE, which costs less and does a better job at augmenting engine sounds that have been degraded by new, efficient engine designs. With QNX Acoustics for Engine Sound Enhancement, automakers can accurately preserve an existing engine sound for use in a new model, craft a unique sound to market a new brand, or offer distinct sounds associated with different transmission modes, such as sport or economy.

The how
QNX Acoustics for Engine Sound Enhancement is entirely software based. It comprises a runtime library that augments naturally transmitted engine sounds as well as a design tool that provides several advanced features for defining and tuning engine-sound profiles. The library runs on the infotainment system or on the audio system DSP and plays synthesized sound synchronized to the engine’s real-time data: RPM, speed, throttle position, transmission mode, etc.




The ESE designer tool enables sound designers to create, refashion, and audition sounds directly on their desktops by graphically defining the mapping between a synthesized engine-sound profile and real-time engine parameters. The tool supports both granular and additive synthesis, along with a variety of digital signal processing techniques to configure the audio path, including gain, filter, and static equalization control.



The value
QNX Acoustics for Engine Sound Enhancement offers automakers numerous benefits in the design of sound experiences that best reflect their brand:

• Ability to design consistent powertrain sounds across the full engine operating range
   
• Small footprint runtime library that can be ported to virtually any DSP or CPU running Linux or the QNX OS, making it easy to customize all vehicle models and to leverage work done in existing models
   
• Tight integration with other QNX acoustics middleware libraries, including QNX Acoustics for Active Noise Control, enabling automakers to holistically shape their interior vehicle soundscape
   
• Dedicated acoustic engineers that can support development and pre-production activities, including porting to customer-specific hardware, system audio path verification, and platform and vehicle acoustic tuning
   

If you’re with an automaker or Tier One and would like to discuss how QNX Acoustics for ESE can address your project requirements, I invite you to contact us at anc@qnx.com.

In the meantime, learn more about this solution on the QNX website.