When Bugs Sing

In The Songs of Insects, Pierce (1949) described the striped ground cricket, Nemobius fasciatus-fasciatus, which chirps at a rate proportional to ambient air temperature. Twenty chirps-per-second tell us it is 31.4 °C; 16 chirps and it is 27 °C. This is a natural example of an auditory display, a mechanism for communicating data with sound. By applying auditory display techniques to computer programming we have attempted to give the bugs that live in software programs their own songs. We have developed the CAITLIN musical program auralisation system (Vickers and Alty, 2002b) to allow structured musical mappings to be made of the constructs in Pascal programs. Initial experimental evaluation [Interacting with Computers (2002a,b)] showed that subjects could interpret the musical motifs used to represent the various Pascal language constructs. In this paper we describe how the CAITLIN system was used to study the effects of musical program auralisation on debugging tasks performed by novice Pascal programmers. The results of the experiment indicate that a formal musical framework can act as a medium for communicating information about program behaviour, and that the information communicated could be used to assist with the task of locating bugs in faulty programs.