Completing the megillah at time of noise

When they read the megillah (the scroll of Esther, which has to be read on Purim) in the synagogue, and the name of Hamman is pronounced and everyone starts making noise, I sometimes fail to hear the cantor. So, I complete the missed words to myself by reading them quietly. I read loudly enough, so that in normal circumstances, I’d be able to hear my own voice, which is enough from halachic point of view. But because of the terrible noise in the synagogue when they say the Hamman’s name, I can’t actually hear myself. Is this enough, or do I have to read loudly enough to hear my own voice above the din?

You should read loudly enough, so as to be able to hear yourself. It’s really a matter of a doubt, whether, when you are reading in a place of great noise, you have to raise your voice to the level that you’d actually be able hear yourself, or whether it’s enough to read at a level that you’d be able to hear yourself if there was no noise. And this is an example — when you read for yourself at the time of clapping and banging in the synagogue during megillah reading, do you have to raise your voice above the noise, or not.

One could bring proof from this week’s portion (“Vaera”). When the frogs invaded Egypt, it says that “Moses shouted unto G-d” (Exodus 8:8). But when he prayed during other plagues, however, it says that he “entreated G-d” (Exodus 8:26, 10:18). The Siphsei Chochomim commentary explains that it says “shouted” because he had to speak above the noise of loudly croaking frogs.