Consider the following scenario if you were at a music concert:
- A singer sings into a microphone
- The sound comes out from the speakers
- The sound from the speaker is picked up by the microphone
- The sound comes out from the speakers
- The sound from the speaker is picked up by the microphone
- ...
This kind of loop can manifest itself in other ways. E.g. happiness breeds success, success breeds happiness which breeds success, and so on.
What’s the best word/phrase that captures this phenomenon?