This article discusses how Sonic Fiction—a concept developed by cultural theorist Kodwo Eshun—can be regarded as a cogent mechanism with which to develop Speculative and Critical Design (SCD) projects, using subjects of sound, music, and listening as their driving force. Through a dissection of the base premises of sonic fictions, this article aims to expand the perspectives taken so far by SCD projects in order to encompass languages other than those informed by the usual theories, as well as to broaden the spectrum of possibilities for sound-based practices within the field. In doing so, it suggests sonic fiction as a decolonial epistemology for assessing design questions.