Hardly ever.
That depends on the sources.
If you have a 100% safe way of producing your MP3 files (as these are the only files that are treated by the named utilities) then you probably do not have to check the files over and over again.
But as I know that you like to get audio from Youtube and perhaps other sources, it may be a good idea to scan these files thoroughly before adding them to the collection.
This is especially true if you run into editing problems.