The invention relates to a sound wave based sensor, comprising an electromechanical film (7) for transmitting and receiving sound waves, an earth electrode (5) being provided on a surface of the electromechanical film (7) and at least one sensor electrode (3) being provided on the surface that is opposite the earth electrode (5). The at least one sensor electrode (3) comprises a plurality of electrode regions (13; 17; 25), each of which can be electrically contacted via at least one web (15).