## 1 Introduction  
Human-robot interactions (HRIs) have been extensively explored over the last decade, contributing to a nuanced comprehension of how humans and robots engage in diverse environments (for a comprehensive review, see: [1]). [PERSON] and [PERSON] [2] state that all interactions between humans and robots require some type of communication. Moreover, speech and language are considered to play a vital role in HRIs [3]. As robots increasingly interact with humans in various areas of their lives, understanding how people perceive emotions in robots is crucial for advancing the research in the field, as well as to improve interactions between humans and robots across different domains. Understanding robot emotions can be achieved by examining the robot's body posture, tone of voice, or facial expressions [4]. Over the past decade, studies have placed significant emphasis on ensuring that robots not only comprehend human emotions, but also respond to them in a personalized manner [5]. This implies that robots must be advanced and capable of conducting detailed analyses of human expressions. Simultaneously, they should possess the ability to distinguish variations in expression, such as those between sexes [6].  
While research into the potential of HRIs has made substantial progress, the capacity of humans to read emotions in robots remains an evolving domain. It is particularly crucial to advance research on the ability of children with special needs to interpret emotions in robots, especially among deaf children. For deaf children, effective interactions with the robot relies on non-verbal communication, as they are unable to hear sounds and voices from the robot. Therefore, it is crucial that the robot can convey its emotional states without sounds. In other words, making the robot's expressiveness as intelligible and direct as possible, without sound, can enable effective and positive engagement between deaf children and the robot. Thus, including deaf children in HRI research can offer profound advantages, that is, the inclusion of this group not only prevents these children from being sidelined in the swiftly evolving domain of robotics, but it can also provide researchers with a more expansive perspective on HRIs when auditory communication is not an option. However, to the best of our knowledge, there are no studies investigating the ability of deaf children to recognize emotions in robots.  
This feasibility study aims to establish the groundwork for further research on interactions between robots and deaf children, by including both deaf and hearing children. Initially, the credibility of a humanoid robot without sound and speech are investigated. Additionally, the ability to recognize emotions in the robot without sound and speech is examined by omitting this feature in a controlled experimental context. Finally, the impact of empathy on the ability to recognize emotions in a robot without sound and speech are investigated.  
Specifically, the following research questions are examined:  
_(RQ1) How do hearing and deaf children assess the credibility of a humanoid robot without sound and speech?_  
_(RQ2) Are children able to recognize emotions in a humanoid robot when they are exhibited through non-verbal communication?_  
_(RQ3) Can empathy affect the ability to recognize emotions, expressed without sound or speech, in a humanoid robot?_  
_(RQ4) Are the children who see a humanoid robot respond to a video in a congruent manner better able to recognize the emotions in the robot compared to children who see a robot respond to a video in an incongruent manner?_  
The remaining parts of the paper is organized as follows: Section 2 reviews the scientific literature that contextualizes this work, focusing on social robots, deaf children, and empathy; Section 3 presents the method and procedure for the experiment. Section 4 present the results of the experiment, while in Section 5, the findings are discussed.