Yes, it is possible to add sound to Issuu publications. The sound file must be placed online and must start playing as soon as the site is accessed, otherwise it won’t be possible for the Issuu reader to start the sound file. The link to the sound file can be inserted when the document is uploaded, but it is also possible to add the sound after publishing.
To add music to a particular publication:
1. Click on the publication you want to add music to, select "Edit" and then "Edit Info" from the dropdown menu.
2. Click on the "Add audio playback" button, and type in the link to the mp3 you want to add to your publication.
3. Click on "Save Changes" after adding your mp3 file, and you should be good to go.