Noise cancellation techniques reduce NVH.

ThePicoDiagnostics NVH Kit from Pico Technology is the cost–effective answer to the many NVH (noise, vibration, and harshness) problems facing technicians today. Providing real-time diagnosis to the technician in the form of either: a bar graph, a frequency chart, a 3D frequency chart, RPM order or road speed view. The ability to start the recording before a road test, and play back the recording for analysis on your return, ensures that driver attention remains on the road. Saving the recordings couldn’t be simpler: much like our other automotive software you simply save the file to your laptop’s hard drive.

But EETimes recently posted an article on how to cancel engine noise and enhance driving experience using noise cancellation techniques improve car audio, solving noise issues and reducing NVH.  It's here - http://bit.ly/1syaGc7