The Alice team has came out with a royalty-free sound library that you can used in the animations. On the page there's also a link so that you can create your own sounds that are compatible with Alice.
http://www.alice.org/sounds/index.php
Further here are the steps for inserting an audio file in the new version of Alice, please follow the steps below.
Project àResource Manager àImport Audio à after selecting the audio file, close the display window.
Next Go to Code EditoràProcedureàdrag the Play Audio to the editor and select the audio imported previously
For instance to play the audio throughout the story,
· Drag and drop Do Together box
· Drag and Drop Play Audio tile into the Do Together box
· Drag and drop Do in Order within the Do Together box
· Drop all the other statements to be executed into the Do in Order