Davening and Krias Shema with a sore on the lip or throat

Question

If someone has a sore on their lip or in their throat, such that it is painful to pronounce certain letters (like the letters that require putting pressure from the upper teeth onto the lower lip or the guttural letters, for example), can they mispronounce words in davening in order to not exacerbate their sore? What about in Krias Shema?

If they are able to produce a similar sound to the painful letter, but not using the exact mouth or throat formation which is supposed to pronounce that letter, is that OK? For example, a similar sound to a ב רפה can be produced without your teeth touching your lips.

Answer 1

From torah.org:

Rambam rules (as is the ruling of the Gemara; see below) that both "audible" and "careful" reading of K'riat Sh'ma are desiderata L'khat'hilah but are not indispensable.

The Mishnah in Berakhot (2:3) cites the following two disputes: "If someone read K'riat Sh'ma and did not hear his own reading, (R. Yehuda says:*) Yatza, R. Yosi says: Lo Yatza. If he read carelessly (without enunciating cleanly and properly), R. Yosi says: Yatza; R. Yehuda says: Lo Yatza." (*the Gemara identifies the anonymous first opinion as that of R. Yehuda; hence the parentheses). The Gemara (Berakhot 15b) rules: The Halakha follows both of them L'kula - leniently (i.e. Halakha follows R. Yehuda regarding "audible" reading; it follows R. Yosi regarding "careful" reading). The understanding of the Halakha, according to R. Yehuda, is that "audible" reading is a L'khat'hilah requirement but, without it, Yatza.

Inferring from the last paragraph, an incorrect pronunciation is fine. A better option may be to use sign language, if possible!