With the rapid advent of touchscreen devices, opportunities are increasing to develop innovative interfaces, including applications that combine touch input with auditory feedback to serve the blind and visually impaired (BVI) community. Targeted to blind high- school children, our innovative design, AEDIN (Acoustic EDutainment INterface), uses non-speech sounds simultaneously as navigational prompts and content icons/signifiers for recorded text-to-speech educational essays, which are the main content of this application. A study of two versions of AEDIN was conducted with 20 participants from a K-12 school for the BVI to evaluate its usability and identify ways to improve it. Through the collection of quantitative and qualitative data, we discovered key design improvements that made AEDIN a highly usable and enjoyable interface for these users. The paper highlights good design practices for acoustic interfaces.