If you want to hear your soundtrack play as you preview your animatic, you must enable audio playback. You can also disable audio playback afterwards if you prefer.
How to enable or disable audio playback
- Do one of the following:
- In the Playback toolbar, click the
Sound button. - In the top menu, select Play > Audio Playback.
Next time you play your animatic, you will hear the sound clips in your audio tracks play. 
Play button in the Playback toolbar.