This thesis applies and evaluates a  framework for sound design drawing on ethnomethodology and conversation analysis (EMCA) to explore how sound design can enhance real-world human-robot interactions. The framework is applied on the case of delivery robots used for last-mile deliveries. After analyzing video material of real interactions involving the delivery robots, workshops were conducted where sound designs were developed using vocal sketching and digital sound prototyping. The sound designs and interactions during the workshops were transcribed and analyzed, resulting in a set of sound design suggestions. These were intended by the designers to enhance interactions by clearly communicating the robots' states and actions, potentially improving safety and accessibility in public spaces as well as positively affecting the perception of the robot. However, testing and broader application is necessary to validate and generalize the sound designs as well as the framework itself. Future work should involve implementing these sounds in real-world settings and exploring the framework's applicability to other robot contexts and other groups of designers.