They are audio waveform preview files. Just leave them in the same folder as your media. No need to open them with anything. You can delete them and they will get rebuilt when you open the media again in Vegas, usually quite quickly (and you can cancel that at the bottom left of the timeline if you don't need them to be built).

They get saved with the media files for a couple of reasons. The major one is that since they get the same name as the media file, putting them in a common folder would cause conflicts should you happen to have video files with the same name in different folders. Keeping it in the same file as the associated media file avoids this conflict. Another important reason is that if you should happen to use the same media in multiple projects, the single .sfk file is sufficient no matter how many different projects it appears in.

Thanks I didn't see that you answered my question and started another thread. Anyway, it is just odd that they show as an adobe reader file within the folders. I'll have to do a better job of keeping every clip of a project in its own folder. As it is most everything is in one library. .

The very first thing i do when starting a new project is to make a new folder for that project, then put all its files in that folder.