## 4 Discussion  
### Discussion of Research Hypotheses  
In this study, we investigated whether regional alarm sound design can reduce driving compliance and improve task performance and experience under an L3 autonomous driving state to alleviate the application restrictions of insufficient interaction design on autonomous vehicles and reduce driving risks. In this study, which supports Hypothesis 1, the same alarm sound has different perceptual results in Shanghai and France. Supporting Hypothesis 2, in the L3 AD state, the ADAS alarm sound based on regional design can effectively improve task feedback performance. Based on the research questions and hypotheses, we conducted the investigation and research of \"sound maps\", \"user expectations\", and \"user perception profiles\" based on the comparison of Chinese and French ADAS alarm sounds, formed the final design guide, and constructed six ADAS alarm sounds for testing.  
In the relevant results of Hypothesis 1, we can see that there are obvious differences between the sounds of the Shanghai sound map and the sounds of the current ADAS. Moreover, in the survey of user expectations, it was found that respondents think that the ADAS alarm sound is difficult to understand, and they hope that the ADAS sound has a real sound. What they look forward to most is the ADAS alarm sound effect of collision and  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Mean (Local)** & **Mean (PSA)** \\ \hline Mental & 43.6 & 91.4 \\ Physical & 10.0 & 17.9 \\ Temporal & 60.7 & 87.1 \\ Performance & 86.4 & 52.1 \\ Effort & 38.6 & 55.0 \\ Frustration & 30.7 & 28.6 \\ Grand total & 18.0 & 22.1 \\ \hline \hline \end{tabular}
\end{table}
Table 16: NASA-LX descriptor comparison.  
collision avoidance. In the result of Hypothesis 2, we adopted a sound design and carried out a simulated driving experiment under the AD state of L3. Compared with the alarm sound of PSA (non-optimized version), the sound design in this study has better reaction time and psychological evaluation results of driving load. It is proven that the ADAS alarm sound based on regional design can effectively improve task feedback performance and reduce the psychological load of drivers.  
From these observations, our research allows us to provide the two following affirmations with strong confidence: First, perception is highly dependent on local parameters. Cultural aspects, road environment aspects, and many other parameters will highly affect the perception profiles of local customers and cannot be neglected. Second, it is, however, possible to improve and adapt Human-Machine Interfaces by applying the methodology described in this paper. By customizing ADASs this way, vehicle users will choose the family of sound they would like to see implemented in their vehicle. Such a process may also increase the sound familiarity and retention regarding these alerts, therefore increasing understandability.  
In addition, workload shows a trend towards lower values in the local guidelines, while overall self-rated performance seems higher in the French guidelines. The reason for this trend may be that French culture has different expectations regarding self-evaluation of performance, leading participants in this cultural context to assess their performance more positively, resulting in higher scores. Different regions have distinct cultural backgrounds. Designing local alert sounds in areas with significant cultural and historical differences can be applied to a wider range beyond just Shanghai, improving the efficiency of sound alerts and enhancing user experience.