A very simple way of playing audio at a trigger only once and not being able to play it again in Unity.
All scripts & assets:
https://github.com/UnityTutorialsHD/Unity-Tutorial-Assets
Music Used:
Cayman Cline - Memos (Prod. BNJMN)
https://twitter.com/CaymanCline
https://www.youtube.com/TheKiDMusicTV
https://soundcloud.com/caymanmusictv