Managing Audio files created by voice-over record

I'm using the voice-over recording feature. The audio files seemed to be stored in my Windows profile directory, not beside the project file. I can't find an option to configure where these files are stored. I'd like them to be stored inside a sub-directory of where my project is located. How can I do this?

Also, I notice that it keeps all recordings I did, even if I end up not using them. Is there a way to delete all the unused recordings?