I deleted project file by mistake

I deleted .aup files for some of my projects. In these projects were only sound what I recorded. It’s almost all files .au still on the project folders, so maybe some of them was deleted too. What can I do to make audio file from all this .au files? Of course I can open one by one .au files in program, but there is too much files more than one thousand files and some projects more than two thousands… Is here some way to create full audio automatially?

Have you checked the recycle bin?
If they’ve gone from there, then see: http://manual.audacityteam.org/o/man/recovering_crashes_manually.html