Can you please specify why do you want the files uploaded as different versions of one file, so that maybe I can offer you some workaround for the functionality you demanded. What you want is not quite possible since the files are of different MIME type in first place, but one option you have is to put an archive for each speaker and pack the 3 files inside (easiest solution, but maybe not what you wanted exactly). Another option is to create a different library or category for each speaker and filter the download list widget to display documents in a certain library / associated with a certain category.
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