Automakers shush cars with noise cancellation technology

[ALS]

Even engineers are surprised by how effective it can be. When it was switched on during tests, "You have a 'wow,'" says Ming-Ran Lee, a Ford noise and vibration engineer.

Chris Woodyard - USATODAY - September 27, 2012

When it comes to creating quieter cars, automakers are giving a whole new meaning to the sounds of silence.

More of them are using technology to mask bad sounds and enhance good ones. Engineers say manipulating sounds in a car adds to perception of quality and harmony.

"Our aim isn't to trick the customer," says Chuck Gray, chief powertrain engineer on Ford's electric vehicles. "It's to give them the best experience."

When it comes to eliminating unwelcome sounds, the new technology works like noise-canceling headphones. A few automakers have used the strategy in luxury cars, and it's now starting to filter down into mainstream models.

"Active noise cancellation works to get rid of noises that customers don't want to hear," says Honda spokesman Chris Martin.... [Read More]

[basjoos]

I hope the noise cancelling technology in these cars doesn't cancel out the siren coming from that fire engine rapidly you approaching from behind or the squeal of brakes from that car that's about to t-bone you. There are some outside noises that you need to hear while driving.

If they would get the Cd well below 0.20, then they wouldn't have any wind noise to worry about cancelling. Also a large component of "road noise" is actually wind noise coming from underneath the car. Add smooth underpanelling and some air splitters/miniboatails to channel air smoothly around the tires to quiet the wind noise under the car.

[brick]

Sirens won't be a problem. This technology is great for canceling out white noise but doesn't do much for things like voices, sirens, etc. Auto makers will still have to do a good job with the conventional sound deadening because I doubt it would make a really noisy car quiet enough to make it worth the trouble.

[300TTto545]

I drove the c-max and didn't realize it had this at the time. It had a very quiet drivetrain and no tachometer.

I drive a HCH-II and if you step on it, the sounds are pretty terrible.

The C-max was certainly quieter (alot) and I could here the engine when I stepped on it - but without a tach, I couldn't really tell how hard I was pushing the engine. I wasn't really sure that it had a CVT! Talk about disconnected....

The HCH-II is certainly not ideal but I don't know how I feel about the feeling of the C-max. You would think we can design efficiency and still have some connection with the car. Without knowing what the engine is doing, you interfere with hypermiling

[50 mpg by 2012]

It occurs to me that a vehicle's sounds are a "passive diagnostic" tool providing instantanious information regarding operating conditions.

This suggests to me that this technology requires the ability to be disabled when/where necessary.

[08EscapeHybrid]

The quest for a quiet car can make them ore dangerous. In the 90's when I drove an ambulance I already had problems with people not hearing the sirens. I also have issue with someone not being able to hear the motorcycle in the lane beside them, and get in an accident. Car horns are another thing that needs to be heard.

The squealing brakes isn't really an issue anymore because most cars on the road have antilock brakes now, and if the brakes do emit any sound, its not that loud. When I was rear ended last month I was stopped at a traffic light in my FEH. Windows down, engine was off. Radio was on, but not loud. I heard nothing until I felt the jolt of being hit.

[herm]

Originally Posted by 300TTto545

The HCH-II is certainly not ideal but I don't know how I feel about the feeling of the C-max. You would think we can design efficiency and still have some connection with the car. Without knowing what the engine is doing, you interfere with hypermiling

I bet engineers could rig up an efficiency feedback, when you exceed EPA you get a mild pleasurable tingle and as you start to waste gas then it starts to get unpleasant.. I bet people would get really good at gliding

[RedylC94]

Compared to conventional sound muffling methods, noise cancellation has the advantage of adding less mass. It also will become less expensive, if it isn't already. Hardly anyone wants a really noisy interior, but beyond some point of reasonable quietitude, adding hundreds of additional pounds of gunk to smother a few more decibels is not an intelligent trade-off, in my opinion. (Looking at you, GM, among others... )

[ItsNotAboutTheMoney]

Silence is only a "problem" because people are accustomed to the loud noise of vehicles, and because people don't like noise manufacturers invest a lot of money to change the noise into sound. I hope that in twenty years time when a higher percentage ofvehicles are electric or electrified that assumption will have gone and instead people will curse the noise made by controlled explosion engines and actually look before they maneuver.

[50 mpg by 2012]

It would be interesting to know how many dB (accoustic power) of noise cancellation is typically used in these types of applications.

This just brought back an experience ... have you ever heard "silence"? It is a strange experience.

One place I worked had a large chamber (probably over 8k cubic feet) to accoustically test sound levels generated by their products. No outside noise, no echo, nothing but "you" ... I suspect some people would have difficulty adapting to such an environment, particularly over an extended period of time.