## 5 Discussion
In addition, prior studies, such as that of [55; 56], have indicated that voice interactions are closely aligned with natural human communication patterns. Further, users who have dysarthria prefer to use their voice to the maximum extent. However, this finding contradicts that of [22], who found that participants rated the usability of eye gaze interactions with SVAs as exceptional, providing an average SUS score of 92.5. However, the limited scope of this study, which focused on a single user who had a disability, raises questions about the generalizability of the findings. Another study, [23], found that users who had a motor disability (but provided no information on their speech ability) gave eye gaze interactions an average SUS score of 78.54, which is higher than our result but lower than that of [22]. A broader participant base in future studies could offer more comprehensive insights into the usability of eye gaze systems. The alignment of the user preferences with usability scores in our study resonates with the technology acceptance model [57] and the unified theory of the acceptance and usage of technology [58]. These models emphasize the ease of use and effort expectancy as critical factors in technology adoption. This is confirmed by our findings, in which participants gravitated toward systems that offered a greater ease of use and less effort, reflecting a natural inclination toward technologies that align with their individual abilities and communication preferences. In addition, interacting through voice is likely to be a more intuitive and natural method [59], even for individuals who have impaired speech capabilities [56]. However, it is important to consider the influence of the participants' lack of prior experience with the eye tracking device and the Daria system. None of the participants had previously used these systems, introducing significant factors that may have affected the system usability, including the intuitiveness required to use the system and the learning curve associated with unfamiliar technologies [60]. Although the Daria system, which uses nonverbal voice commands, relies on the inherent familiarity most individuals have with vocal communication, making it more intuitive, eye tracking systems may require a steeper learning curve because of their unconventional interaction mode. Therefore, these factors may influence the overall usability of each system for first-time users [61], underscoring the importance of considering the novelty and intuitiveness of HCI technologies in their evaluation. These findings are further supported by our workload results, which offer important insights into the experience of users who have dysarthria when interacting with various technologies. The data show that eye gaze interactions involve considerably more effort across several dimensions. This higher level of workload suggests that although eye gaze interactions remain a viable option for individuals who have dysarthria, especially those who have severe cases, the extensive demands may affect this technology's practicality and acceptance for long-term use. This has been noted in prior studies [62], suggesting that the burdensome nature of eye gaze interactions may extend to other populations who have similar challenges. Further, the perceived effectiveness and reduced effort associated with voice-based interactions suggest a higher likelihood of long-term acceptance and use. Their ease of use and lower physical and mental demands position these methods as more sustainable and practical for individuals who have dysarthria. This aligns with the broader goal of assistive technologies, which is to enhance the quality of life through user-friendly and efficient solutions [63]. Therefore, our findings underscore the critical need to consider the workload and user effort as key factors in the design and implementation of HCI methods, specifically, in terms of assistive technologies for individuals who have dysarthria.