Enhance "Enhance Speech" manualy?

In a roughly 3-second original sound clip, I have a few microphone “rumbles.” Enhance Speech removed them surprisingly well. Unfortunately, the result is too muffled and too loud, and does not match anymore to the other original sound. I also cut the original sound clip by one word. When I try to optimize the only 7 frames longer version with just the additional word “The” with Enhance Speech, the “rumbles” are no longer removed. Very mysterious. I can see somewhere what exactly Enhance Speech did that I optimize it manually?