Related על ברכות 3:4

A man who had a seminal emission (Baal Keri) and is sick, if nine Kavs of water were poured on him, he may read [the Shema]. But he may not fulfill the obligation [of reading the Shema] for others until he dips himself in forty Seah [of water]. Rebbi Yehudah says, “Forty Seah no matter what."

“A man who had a seminal emission (Baal Keri) who does not have water to dip in may read the Shema, but he may not [read it loud enough so that he can] hear [himself talking] with his own ear, and does not say the Beracha (blessing) not before it and not after it.” [These are] the words of Rebbi Meir. And the Chachamim (Sages) say, ”He may read the Shema and he may [read it loud enough so that he can] hear [himself talking] with his own ear, and he says the Beracha [both] before it and after it.” Rebbi Meir said, “One time we were sitting in the Bet Midrash (Study Hall) in front of Rebbi Akiva and we were reading the Shema, but we were not saying it loud enough to be able to hear ourselves, because of one inquisitor who was standing by the door.” They (i.e. Chachamim) said [back] to him, “The time of danger is not a proof.”