Hello Tiscéo,
Welcome to Microsoft Q&A.
Thank you for sharing the test information with us.
Based on the error code and your description of the problem, I think this issue might stem from a system error or the damage or loss of the corresponding component files, rather than an abnormality with the microphone.
So I would give priority to recommending that you try to make a quick fix to the system:
The two codes mentioned in the link are both commonly used repair commands. Please feel free to test them. If I'm lucky, I believe this problem will be fixed.
If it doesn't work, my direct suggestion is to reset your Surface. Please back up all important data before attempting this step. After completing the backup, click the Start menu - Settings - System - Restore - Initialize yourcomputer.
This is a relatively quick reset process and usually doesn't take too long. However, if resetting the Surface still fails to fix the Voice Access issue, then I'm afraid you will need to use a dedicated USB recovery drive for Surface to restore your Surface to factory Settings. Here is a complete tutorial:
Création et utilisation d’un lecteur de récupération USB pour Surface - Support Microsoft
If you don't want to read a lot of text, there are video steps for reference in the link. Please be sure to follow the instructions to complete all of this. If your Surface has no hardware malfunctions, then this process is usually effective.
Best Regards,
Ian | Microsoft Q&A Support Specialist