Unfortunately Dropbox intentionally decided to break all the millions of hyperlinks for all of their millions of customers as part of a service change. To say the least, I and many others are in the process of pulling our services at Dropbox.
In reference to the files, let me see if I can find them. In the meantime, you can search for me on Soundcloud.com and hear similar studies. Go to SoundCloud.com and search on “Lowboy Bootay.” That should bring you to list of a number of recordings and experimental studies.