Q. An aged person that can’t speak and recite the Viduy (confession for sins done), listen to someone else saying it and comply as ‘Shomea Keone’ or one that listens is like he has said it also, as is done with kiddush. Is that recommended and helpful?
A. Horav Dovid Pam Shlit’a pointed to the Mishna Berura (607: 11), that explains that the above is a difference of opinion between the Shulchan Aruch (ibid) and the Remah, if once one has already said a viduy, and now it is repeated and expanded by the Shaliach Tzibur, if it suffices by just with listening or one has to repeated again, as the Rema advises.
They seem to disagree in the point above. The Rema adds that it is the custom in our days to repeat it.
In our case, since there is no other option, the one that can’t speak should indeed pay attention to the Shaliach Tzibur or have someone else read it for him.
Rabbi A. Bartfeld as revised by, Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit'a