How to hide e-book files from folder "all songs"

[curbi1]

Hello

I have just bought a Sony NWZ-E453, that supports e-books

On my computer I created a folder named “ebook” and copied the ebooks in there

When I turn the mp3 player on I can see the folder and the ebook files

But: I also find these e-book files in the folder “all songs” (I think as there are mp3 files)

When I know want to listen to music with folder “all songs” I have e-book files in between the music-files

Is there a possibility not to have these files in that folder? Do I have to copy them in another way or name them different? Can I title them as "non music files"?

Thanks in advance for your help