Question: When a person has an aliyah, should he recite the phrase “Baruch Hashem ha’mevorach l’olam va’ed” together with the congregation or should he wait for the congregation to conclude and then recite this phrase by himself?
Answer: HaRav Shimon Schwab, zt”l (Rav Schwab On Prayer, pp.252, 253) discusses this question. He explains that “Baruch Hashem ha’mevorach” is deemed a davar sh’bekedushah which requires the presence of a minyan. Accordingly, a person having an aliyah should say the phrase simultaneously with the congregation.
HaRav Schwab notes that whenever he was called to the Torah, he personally would recite “Baruch Hashem ha’mevorach l’olam va’ed” together with the congregation. This was also the minhag of his kehillah.
However, this psak is contrary to the general custom. We may perhaps justify the general practice based on the following: The Mishnah Berurah (Orach Chayim 104:28) notes that if a person is in the middle of Shemoneh Esrei when Kedushah starts, he should be silent and pay attention to the prayer of the shliach tzibbur. That way, it will be considered as if he said Kedushah himself since the shliach tzibbur is supposed to include everyone in his prayers.
If so, perhaps one can argue that every word out of the chazzan’s mouth is a “communal prayer” in a sense. Therefore, whatever he says – even a prayer he says himself – is considered “communal.” Thus, even if he says “Kadosh, kadosh, kadosh” in Kedushah by himself (and not when the congregation says it), those words are considered part of a communal prayer.
We can extend this argument to the berachot a person says when he has an aliyah. Even though “Baruch Hashem ha’mevorach l’olam va’ed” is a davar sh’bekedushah which requires a minyan, he can still say it himself. It will be considered a communal prayer nonetheless.
I once asked my father-in-law, HaRav HaGaon Rav Yaakov Nayman, z”l, a protégé of the Brisker Rav, what the custom of his teacher was. He answered that the shliach tzibbur should recite “Kadosh, kadosh, kadosh” together with the congregation – not subsequent to it.