  In this paper, we illustrate our work on improving the accessibility of
Cyber-Physical Systems (CPS), presenting a study on human-robot interaction
where the end-users are either deaf or hearing-impaired people. Current trends
in robotic designs include devices with robotic arms and hands capable of
performing manipulation and grasping tasks. This paper focuses on how these
devices can be used for a different purpose, which is that of enabling robotic
communication via sign language. For the study, several tests and
questionnaires are run to check and measure how end-users feel about
interpreting sign language represented by a humanoid robotic assistant as
opposed to subtitles on a screen. Stemming from this dichotomy, dactylology,
basic vocabulary representation and end-user satisfaction are the main topics
covered by a delivered form, in which additional commentaries are valued and
taken into consideration for further decision taking regarding robot-human
interaction. The experiments were performed using TEO, a household companion
humanoid robot developed at the University Carlos III de Madrid (UC3M), via
representations in Spanish Sign Language (LSE), and a total of 16 deaf and
hearing-impaired participants.
