Yes, you can!
Once you've played a clip in a mission, it's permanently unlocked. To listen to the clip again:
- Find the mission in the Missions tab
- Tap Listen to [X] Story Clips
- Tap the clip you want to listen to again
You can also listen on the ZombieLink website:
- Log in to ZombieLink
- Visit the Series page
- Find the mission you want to listen to (all of Zombies, Run! is under The Abel Township Saga)
- Select the clip you want to listen to again