This article introduces the employment of rhetorical strategies as an innovative methodological tool for non-verbal sound design in Human-Computer Interaction (HCI) and Interaction Design (ID). In the first part, we discuss the role of sound in ID, rhetoric, examples of rhetoric employment in computer sciences, and existing methodologies for sound design in ID contextualized in a rhetorical perspective. On this basis, the second part of the article proposes new potential guidelines for sound design in ID. Finally, the third part consists of a case study. The study applies some of the proposed guidelines to the design of short melodic fragments for the sonification of common operating system functions. The evaluation of the sound design process is based on a learning paradigm. Overall, the results show that subjects can more effectively learn the association between sounds and functions when the sound design follows rhetorical principles. The case study focuses on a very specific instance in the extensive field of auditory display and sonic interaction design. However, the results of the validation experiment represent a positive indication that rhetorical strategies can provide effective guidelines for sound designers.