You have the option to turn the Noise Cancellation on and off by using the switch that is located on the right side of the NC box. When choosing the switch option, you will see a green light inside the the switch will indicate that the Noise Cancelation is on. To turn off the Noise Cancelation, move the switch down towards the cable and the green light will turn off. When charging this device with the micro USB charging cable included in the packaging, you will see the light turn orange to indicate that it is charging.