Using the Pepper Robot to Support Sign Language Communication

Abstract

Social robots are increasingly experimented in public and assistive settings, but their accessibility for Deaf users remains quite underexplored. Italian Sign Language (LIS) is a fully-fledged natural language that relies on complex manual and non-manual components. Enabling robots to communicate using LIS could foster more inclusive human robot interaction, especially in social environments such as hospitals, airports, or educational settings. This study investigates whether a commercial social robot, Pepper, can produce intelligible LIS signs and short signed LIS sentences. With the help of a Deaf student and his interpreter, an expert in LIS, we co-designed and implemented 52 LIS signs on Pepper using either manual animation techniques or a MATLAB based inverse kinematics solver. We conducted a exploratory user study involving 12 participants proficient in LIS, both Deaf and hearing. Participants completed a questionnaire featuring 15 single-choice video-based sign recognition tasks and 2 open-ended questions on short signed sentences. Results shows that the majority of isolated signs were recognized correctly, although full sentence recognition was significantly lower due to Pepper's limited articulation and temporal constraints. Our findings demonstrate that even commercially available social robots like Pepper can perform a subset of LIS signs intelligibly, offering some opportunities for a more inclusive interaction design. Future developments should address multi-modal enhancements (e.g., screen-based support or expressive avatars) and involve Deaf users in participatory design to refine robot expressivity and usability.