OK I got the answer. The fields that you see in the image I posted are comments not form fields. There are supplied comment fields for the file, in this case a wav file, which can be edited (renamed) or removed and the user can add commenting fields.
Here is what I found:
Note:
You must have Acrobat Pro installed to enable commenting for Reader users in managed reviews. You cannot enable commenting for Reader users using Acrobat Standard.
What a bummer!!