Simple gestures such as stroking or tapping of a surface (10) can be used to control common functions of electronic systems (16) by positioning one or more sensors (12) on the surface and detecting sounds generated by the interaction with the surface. Signals corresponding to detected sounds are filtered and interpreted either in the system to be controlled or else in the sensors themselves. The direction of movement of a hand (18) stroking the surface can be interpreted as a command to increase or decrease a parameter, such as the sound volume level of a television, for example. Determination of the position of the user's hand is unnecessary. The apparatus is therefore simple, inexpensive, robust and discrete, requiring only a minimum of installation and without being necessarily dedicated to a particular electronic system to be controlled.