Q. Our megilla Baal Kore, with the passing of years, now needs a hearing aid. He can still hear without it, when you talk loudly to him. Can he still read the megilla in shul for all, or do we need someone else? (he will be hurt if denied).
A. Shulchan Aruch (O.H. 689: 2) and Mishna Berura (ibid. 5), rule that one that can talk but is totally deaf, cannot read the megilla for others, since there is a requirement for pirsume nissa, or publicizing the miracle regarding megilla reading. Mishna Berura quoting Shaarei Teshuva asserts, that the above applies only when he cannot hear at all, but if he hears when being addressed loudly he may read for others.
However, Tzemach Tzedek (E.H. 323) maintains that if he reads with a normal voice that he cannot hear himself, they do not comply. (See Piskei Teshuvos ibid. who quotes more lenient opinions).
Horav Shlomo Millers’ Shlit’a opinion is that if he reads loud enough, that he can hear himself without the hearing aid, he can read lechatchila (on the onset) for others.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a