Toyota develops noise-cancelling system for cars

Posted Wed Jul 16 2008 5:32 PM by Siddharth Raja

Expanding on the same concept used in noise-cancelling headphones, Toyota has developed a noise cancelling system for its Japanese-market Crown Hybrid that nearly eliminates engine sound within the passenger compartment. The system uses a complex system of microphones, speakers and sensors located around the cabin.

Like the headphones, the new Toyota system works by using small microphones to monitor surrounding sounds, then plays back frequencies mathematically calculated to be the exact opposite of the ambient noise through the speakers, causing both sound waves to collide and cancel each other out. The Toyota system has an extra sensor that takes into account engine rpm.

Debuting in the Crown Hybrid, the system was developed to cancel the annoying hum of the engine at low rpms when driving around town.

Toyota isn’t the first to develop such a system for cars. Lotus had developed similar systems as far back as 1990, and a trio of Mazda engineers having written a scholarly paper to the Society of Automotive Engineers detailing a nearly identical system in 1994. Acura, too, has a similar system dubbed Active Noise Cancellation (ANC), which it uses on a number of models.

Reader Comments

Wed Jul 16 2008 8:45 PM
wheelin&dealin says

Acura has had Active noise cancellation in the RL since 2005, the sames system has been on the Acura TL type S since 2007...Just goes to show you how much further Honda motor company is ahead of Toyota in automotive technologies.
Wed Jul 16 2008 8:54 PM
Guber says

I like how the Crown looks, especially the grill.
Thu Jul 17 2008 8:50 AM
Guy says

This car should replace the Avalon.
Fri Sep 12 2008 4:10 AM
NMC says

Very nice crown,it is available in 2.5 and 3.O l v6 and will have vdim tecnology
Wed Oct 15 2008 5:33 AM
mbmama says

A similar noise cancellation system according to my knowledge was developed by Volkswagen in the 1960's. They put a speaker on the two inner sides of the headrest on both the front seats, so that a speaker was directed towards each ear. A sound having a frequency equivalent to the typical drivetrain noise of a Volkswagen was emmited through each of these speakers thus providing a noise free ride to the driver and the front passenger.
Best regards,
Mickey B. Mama

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