Abstract: A three dimensional touch sensing system having a touch surface configured to detect a touch input located above the touch surface is disclosed. The system includes a plurality of capacitive touch sensing electrodes disposed on the touch surface, each electrode having a baseline capacitance and a touch capacitance based on the touch input. An oscillating plane is disposed below the touch surface. A touch detector is configured to drive one of the touch sensing electrodes with an AC signal having a frequency that shifts from a baseline frequency to a touch frequency based on the change in electrode capacitance from the baseline capacitance to the touch capacitance. The touch detector is configured to drive the oscillating plane to the touch frequency.