Abstract: A switching matrix adapted to interface blind persons with electronic signals of the type used to drive a visual digital display device is disclosed. The matrix includes at least one series of raised electrically conductive terminals grouped into sets of braille coded characters representative of the digits 0 through 9 mounted on, but insulated from, an electrically conductive substrate. Each set is adapted to short circuit to the surrounding substrate when touched with a fingertip, thus forming a touch controllable switch.An electronic circuit employing the matrix is also disclosed which produces an audible signal when the user touches a set of the terminals energized by a signal driving the corresponding digit of a visual digital display device.