The cockpit of a can can be a noisy place to listen to music. Of the three sources of noise–engine, wind and road–the last is the worst. Tires rolling on pavement can be awfully loud. This is where GizMag picks up the story:
As automakers attempt to make vehicles more energy-efficient, they’re increasingly turning to lighter building materials. While doing so may indeed result in lightweight cars, these materials generally lack the sound-dampening qualities of their heavier counterparts. That’s why Harman and Lotus Engineering have developed the HALOsonic system, which cancels out road noise by making noise of its own.
Automakers such as GM and Toyota have already created active noise cancellation (ANC) systems that use sound to minimize engine noise. They do so by analyzing the engine noise within the cabin, and then generating a sound wave that has the same amplitude but an inverted phase. As a result, the sound waves from the engine and the ANC cancel each other out, so neither are heard by the passengers. It’s the same principle used by noise-canceling headphones.
But this is trickier than it sounds. Keep reading.