Don't know what triggers it. I do not know if this is the same problem as yours but here is what I did when it happened to me. I took the battery out then I wrapped one time around with a loosly woven gause from the medical cabinet . Then I placed the aid inside a small bag of rice and put that bag on a dry shelf for three days. Then I took the aid out of all that and hair dried it with a hair dryer, making sure I did not get it too hot. Evidently it pickup moisture from water in my ear from a shower, or laying the aid on a table with water, sweating too much, or high humidity. It worked.
