Beneath the hob, induction coils made from copper wire create a magnetic field as electricity is passed through them. If a pan with a magnetised base is placed on the hob, the magnetic field causes it to heat up directly. The hob will remain cool, with only some residual heat from the pans. Non-magnetic pans put in the same place will remain cold. To cool the electronic components underneath the glass ceramic, a fan is set in motion that can automatically turn itself on during cooking. It runs until the appliance is sufficiently cooled and then automatically turns itself off. Depending on the material and finish of the cookware, various other noises can be heard when the hob settings are on high, such as humming, whistling or chirping. If the heat is turned down during cooking, these noises can hardly be heard. At low settings, a quiet clicking can be heard that is caused by the electronic components.