There is a person who is not able to daven on his own because he r”l had a stroke and it takes him very long to say the words. Therefore, the eitza that is done is someone stands next to him by SE and davens in a way that is audible to him (e.g., by Maariv or by Mincha when there is no chazaras hashatz in yeshiva). Is this permitted – as one cannot raise his voice during SE?
The issue primarily is regarding be motzei someone else with SE, nevertheless, it is permitted in such circumstances. Although in normal situations we are not motzei an individual with davening however in such a case it is permitted. In fact I personally did this for Horav Zaidel Epstein zt”l during the last period of his life when he wasn’t capable of talking.
Shulchan Aruch O:CH 594, M:B ibid 2.