Question: Is there any way to restore audio files deleted from sync folders
Yes, but only if you have not emptied the recycle box / deleted items .
There are 2 ways of recovering deleted items, as below:
1) Go into Recycle box folder, right click on file and left click on the restore option
2) Select the file with left click and simply drag over to the folder that you would like to restore the file
please see video on below link: