Phantom rings - open questions

[Rosuav]

• What is normal idle state and normal bell ring?
• When it creeps up (if that's what happens), does it ever revert to original normal?
• When phantom rings occur, would a real ring cause an even higher status? (Or lower, if a ring is a lower state)
• Conclusion: What does it take to either reset the state to normal, or readjust the thresholds?