Abstract topics such as recursion are challenging for many computer science students to understand. In this experience report, we explore function sonification—the addition of sound to a function to communicate information about the function’s behavior in real-time as it runs—as a pedagogical approach for improving students’ understanding of recursion. We present several example iterative and recursive function sonifications, plus spectrograms that illustrate their different sonic behaviors. We also present experimental evidence that using these sonifications significantly improved the understanding of recursion for students who used them, compared to students who used silent (i.e., traditional) versions of the same functions. Based on these experiences, we believe sonification has under- appreciated potential for teaching abstract computing topics.