How do I add audio in Twixl Publisher apps ?

Audio files can be embedded in the publication via the Window -> Interactive -> Media palette. You can add an audio file in MP3 format.
If you insert an MP3 audio file, you can place any type of button or text object on top of it. Clicking that object on the iPad will play/stop the sound sample.

Audio options can also be controlled from the Twixl Publisher Palette.
palette_sound.png

Here you can control the relevant options for sound clips.
"Loop": provides a continuous playback of your sound clip.
"Play on page load": will automatically start a sound clip when a user navigates to that page.