## 5 Discussion  
This study contributes significantly to the field of HCI and the accessibility of HCI technologies. By examining three distinct HCI methods--direct speech commands, non-verbal voice cues via the Daria system, and eye gaze interactions--our study not only reveals their effectiveness, usability, and participant preferences but also provides a com \begin{table}
\begin{tabular}{c c c} \hline \hline
**Preference** & **Participant** & **Diagnosis** \\ \hline Alexa & P1 & Mild \\ Alexa & P5 & Moderate \\ \hline \multirow{4}{*}{Daria} & P2 & Mild \\  & P3 & Mild \\  & P6 & Severe \\  & P7 & Severe \\  & P8 & Severe \\ \hline Eye gaze & P4 & Moderate \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Participant preferences for assistive communication systems. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Category** & **System** & **Mean** & \(p\)**-Value** & \(p\)**-Value Assessment** \\ \hline \multirow{4}{*}{Mental demand} & Daria & 93.75 & 0.223 & Not Significant \\  & Eye gaze & 43.75 & 0.317 & Not Significant \\ \cline{2-5}  & Daria & 93.75 & 0.317 & Not Significant \\ \cline{2-5}  & Alexa & 77.08 & 0.223 & Not Significant \\ \hline \multirow{4}{*}{Physical demand} & Daria & 93.75 & 0.025 & **Significant** \\  & Eye gaze & 52.08 & 0.025 & **Significant** \\ \cline{2-5}  & [PERSON] & 93.75 & 0.317 & Not Significant \\ \cline{2-5}  & [PERSON] & 95.83 & 0.024 & **Significant** \\ \hline \multirow{4}{*}{Temporal demand} & [PERSON] & 89.58 & 0.020 & **Significant** \\  & Eye gaze & 64.58 & 0.020 & **Significant** \\ \cline{2-5}  & [PERSON] & 89.58 & 0.285 & Not Significant \\ \cline{2-5}  & [PERSON] & 87.50 & 0.205 & Not Significant \\ \hline \multirow{4}{*}{Performance} & [PERSON] & 93.75 & 0.041 & **Significant** \\  & Eye gaze & 62.50 & 0.655 & Not Significant \\ \cline{2-5}  & [PERSON] & 89.58 & 0.242 & Not Significant \\ \hline \multirow{4}{*}{Effort} & [PERSON] & 95.83 & 0.018 & **Significant** \\  & Eye gaze & 43.75 & 0.564 & Not Significant \\ \cline{2-5}  & Eye gaze & 43.75 & 0.042 & **Significant** \\ \hline \multirow{4}{*}{Frustration} & Daria & 89.58 & 0.068 & Not Significant \\ \cline{2-5}  & Alexa & 77.08 & 0.461 & Not Significant \\ \cline{1-1} \cline{2-5}  & Eye gaze & 64.58 & 0.498 & Not Significant \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Pairwise workload statistical analysis and significance. The significance level is 0.05.  
prehensive comparison of these methods. These findings are highly valuable for future researchers in this field and contribute to the development of more inclusive and accessible communication technologies. The diverse preferences expressed by the participants in our study revealed a nuanced picture of interactions with SVAs. Our findings indicate a preference for the Daria system among most of the participants, which is attributed to its ease of use and adeptness at understanding commands. This preference was particularly notable among the participants who had severe dysarthria, suggesting that Daria's design is well suited to users who have significant speech impairments. This finding shows how using nonverbal voice cues, which is within users' capabilities, aligns with [PERSON]'s principles, specifically, ability-based design principles [54], for creating systems in accordance with the strengths and capabilities of users, thereby enhancing accessibility. However, Alexa was preferred by the participants who had milder forms of dysarthria, indicating its effectiveness for users who can articulate clearer speech patterns. The eye gaze interaction was uniquely valued by a participant who had moderate dysarthria, highlighting its potential as an alternative communication method for those who find voice-based interaction challenging. These preferences correlate with our findings on usability, which indicate that SVAs that use verbal or nonverbal commands are more usable those those using eye gaze interactions. This increased usability arises from the relative ease of speaking and the ability of the device to understand speech.