SpeaK is a sound lexicon that offers definitions of main sound properties. Each term of the lexicon is illustrated by sound examples that have been created or recorded on purpose, in order to highlight the given property. The tool is embedded in a Max interface, developed by Frederic Voisin, that can be customized by adding new terms and/or sounds according to the needs of a given usecase. One goal of SpeaK is to foster a shared understanding of sound phenomenons, in the frame of a collaborative sound design process. For that, it is often associated with Intermediary Objects of conception (typically, a card set) that allow to transpose general insights into sound characteristics, and then inform the final stage of sound design. Since few years, the ergonomics of Speak have been especially developed thanks to different sound design projects that will be detailed during the presentation and will serve as an illustration of the validity of this approach.