Fusion's Active Noise Cancellation — If you don't hear it, is it really there?

(September 29, 2012) DEARBORN, Mich. — Powertrain noise in the all-new Ford Fusion Hybrid is like the proverbial tree that fell in the forest. With Active Noise Cancellation technology on board, if you don’t hear it, is it really even there?
Active Noise Cancellation technology helps enable the 2013 Fusion Hybrid sedan to deliver EPA-certified 47 mpg city and 47 mpg highway ratings that combine for 47 mpg overall.
The fuel economy connection may not be obvious, but Active Noise Cancellation allows Ford engineers to tune the car for more fuel-efficient operation. Calibrating an engine requires careful balance between delivering the desired performance with the lowest possible fuel consumption and emissions, all while keeping it pleasant to drive.
“The Fusion Hybrid leverages this advanced technology to help deliver maximum fuel economy for the customer,” said Henry Ford Technical Fellow for NVH (Noise, Vibration and Harshness) Dr. Takeshi Abe. “Reduced powertrain noise in the passenger compartment becomes the icing on the cake.”
At the lower speeds that help efficiency, engines produce booming, low-frequency sounds that can be unpleasant to the driver and passengers. Without Active Noise Cancellation, engineers have to keep the engine out of this operating range, sacrificing efficiency.
Yet to achieve peak fuel economy, a creative solution must be applied harnessing advanced audio technology to eradicate this unwanted sound.
A predictive control system notes driver behavior and how the engine responds, anticipating noise before it is even generated.
Three highly sensitive microphones are mounted in the Fusion Hybrid’s interior headliner — two over the first seating row and one over the rear – to detect and measure engine noise. These microphones send a signal to the Active Noise Cancellation control module in real time.
The module instantaneously and continuously generates opposing sound waves. This reversed wave is directed through the Fusion Hybrid’s audio system, combining with the original engine noise wave to cancel out any potentially objectionable sound.

The combination of the proactive and reactive signals ultimately provides a more pleasing effect for driver and passengers.


The infographic above depicts Active Noise Cancellation technology at work, showing the movement pattern of sound travel within the car. The lower panel depicts the cancellation of unwanted sounds, resulting in minimized residual noise.