xi, 79 p. ： ill. (some col.) / Graphics provide a rich display medium that facilitates identification of spatial patterns but are inaccessible to people who are blind or low vision. Audio provides an alternative medium through which to display information. Prior research has explored audio display of lines representing functions and location of screen objects within a graphical user interface; however, presentation of spatial attributes of lines (angle, number of segments, etc.) of geographic data has received limited attention. This thesis explores a theoretical foundation for designing audio displays and presents an experimental evaluation of line symbology. Sighted users who were blindfolded and blind users performed a line following task and a matching task to evaluate the line symbology. Observed differences between the conditions did not reach statistical significance. User preferences and observed strategies are discussed. / Committee in charge: Dr. Michal Young， Chair