A capacitive touch sensor of the type employing adjacent drive and sense electrodes, in which an additional sense electrode Y1 is provided as well as the conventional drive electrode Xn and sense electrode Y0. The drive and two sense electrodes are arranged on the bottom side of a dielectric panel, the top side providing—a sensing surface to be touched by a user's finger or a stylus. The additional sense electrode is positioned on the underside of the dielectric panel so that it is shielded from the drive electrode by the conventional sense electrode. As a consequence, the conventional sense electrode is much more sensitive to the proximity of the finger or stylus than the additional sense electrode which primarily registers noise. The signal collected form the additional sense electrode is then subtracted from the signal collected from the conventional sense electrode, thereby to cancel noise. Another design provides similar functionality with a capacitive touch sensor of the type employing single-ended electrodes.