An interface apparatus (1600A, 1600B) comprising: - a touch input section (1640 - 1644); and - a tactile output section (1660 - 1664); wherein the touch input section comprises: - a touch surface arranged so as to be touched or approached by a bare body member, wherein the touch surface has at least one touch-sensitive area; - and wherein the touch input section comprises or is operatively connectable to data processing means (1602 - 1608) for assigning at least one function to the least one touch-sensitive area; - wherein the touch input section comprises presence-detecting means (1640, 1648) for detecting a presence or absence of the bare body member near the at least one touch-sensitive area; and wherein the tactile output section comprises an electrosensory generator, which comprises: - one or more conducting electrodes, each conducting electrode being provided with an insulator wherein, when the bare body member touches the conducting electrode, the insulator prevents flow of direct current from the conducting electrode to the bare body member and a capacitive coupling over the insulator is formed between the conducting electrode and the bare body member; - a voltage source (100, 102, 104) for applying an electrical drive to the one or more conducting electrodes, wherein the electrical drive comprises a first frequency component in a frequency range between 1 Hz and 1000 Hz; - wherein the capacitive coupling and electrical drive are dimensioned to produce an electrosensory sensation; and - whereby the electrosensory sensation is produced independently of any mechanical vibration of the one or more conducting electrodes or insulators; wherein the tactile output section further comprises sensation-variation means (1660, 1668) configured to receive an input from the presence-detecting means (1640, 1648) and to temporally vary the electrosensory sensation based at least partially on input from the presence-detecting means; and wherein the interface apparatus shares a conductive layer (1642, 1662) between the touch input section and the tactile output section. - a touch input section (1640 - 1644); and - a tactile output section (1660 - 1664); - a touch surface arranged so as to be touched or approached by a bare body member, wherein the touch surface has at least one touch-sensitive area; - and wherein the touch input section comprises or is operatively connectable to data processing means (1602 - 1608) for assigning at least one function to the least one touch-sensitive area; - wherein the touch input section comprises presence-detecting means (1640, 1648) for detecting a presence or absence of the bare body member near the at least one touch-sensitive area; - one or more conducting electrodes, each conducting electrode being provided with an insulator wherein, when the bare body member touches the conducting electrode, the insulator prevents flow of direct current from the conducting electrode to the bare body member and a capacitive coupling over the insulator is formed between the conducting electrode and the bare body member; - a voltage source (100, 102, 104) for applying an electrical drive to the one or more conducting electrodes, wherein the electrical drive comprises a first frequency component in a frequency range between 1 Hz and 1000 Hz; - wherein the capacitive coupling and electrical drive are dimensioned to produce an electrosensory sensation; and - whereby the electrosensory sensation is produced independently of any mechanical vibration of the one or more conducting electrodes or insulators;