If you want to extract attachments from PDF such as audio, video, etc., then these free PDF extractor software and online services will help.

To add the audio comment to the PDF in Acrobat, look for the paperclip icon on the comment toolbar. The paperclip icon has a plus on it as well. This icon is the Add a new attachment button ...

After you add an attachment field to an Access table, you can import PDF files into any of the table's rows. You can then view them from within Access because they become part of your database.