"I hear the pattern": interactive sonification of geographical data patterns

Interactive sonification (non-speech sound) is a novel strategy to present the geographical distribution patterns of statistical data to vision impaired users. We discuss the design space with dimensions of interaction actions, data representation forms, input devices, navigation structures, and sound feedback encoding. Two interfaces were designed, one using a keyboard and another using a smooth surface touch tablet. A study with three blind users shows that they are able to perceive patterns of 5-category values on both familiar and unknown maps, and learn new map geography, in both interfaces.