Every voice message that is sent in Sdui via the corresponding function is saved in a folder provided for this purpose in the cloud of the respective chat.
The folder is called "Voice Memos" and is created once the first voice message is sent into the chat, similar to the "Chat Attachments" folder.
You can find the folder by going to the chat you want and then clicking the cloud icon in the top right corner.
The voice messages can be deleted from the cloud folder by the admin of the group/chat, but then they are no longer available in the chat either. Likewise, if the voice memo is deleted in the chat, the file will disappear from the cloud folder.