Removing unwanted file types from media library

[Andy L]

I installed Subsonic 4.7 and did a scan of my media folders, which picked up the .wav files in my collection which I didn't want to be added. I then deleted 'wav' from the list of Music file types in Subsonic and then clicked on Clean up database to get rid of them but they're still showing up. I have set my media folders to be scanned every day at 2am but this hasn't made any difference either - how do I stop those .wav files from showing up in my library? Thanks in advance!