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.

Free access also allows you to add comments to PDFs, in addition to allowing you to download and print them. It’s when you get to things like trying to convert a PDF into a Microsoft Word ...

Until now, folks who wanted to add comments to a PDF document had to have a version of Acrobat, Adobe's collection of PDF authoring tools, said Pam Deziel, director of Acrobat product marketing ...