This document discusses noise cancellation techniques used in cars. It describes how engine and wheel vibrations propagate as structure-borne sound through the car body and radiate as airborne noise inside the cabin. It outlines passive and active approaches to vibration control and noise control, including using sensors, controllers, actuators and generating canceling signals to reduce noise. Mathematical models of road noise, female voices, male voices and the resultant output with cancellation are shown. The goal of active noise cancellation is to identify sound waves by frequency and generate counteracting waves to reduce overall noise levels in the vehicle.