Can the Larsen effect help explain how overunity resonance devices function ?

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Can the Larsen effect ( https://en.wikipedia.org/wiki/Audio_feedback )  help explain how overunity resonance devices function ?

For those of us who still don't understand how these  overunity resonance devices function .

Also, it seems that if you just directly connected an  electret-?-microphone to a speaker,  without any type of external power input,  that it could never become overunity because the micophone and speaker are very inefficient,  so the losses would prevent overunity.
    -  But what about if you put a very loud constant sound to the microphone,  to get enough power travelling through the loop to overcome the  inefficiency / losses,  although I still doubt that would work .