Q. (Re question above) Do all Poskim agree that one listening to the sheliach tzibur and the tzibur answering Amen, Kedusha, Kaddish, Barchu, etc, has to stop learning and is required to answer?
A. From Shulchan Aruch (O.H.55: 20) it would seem that one can answer if he so desires, but is not obliged to do so. Others maintain, that if he is able to answer and is not himself engaged in a section of the tefila one cannot interrupt, he is obliged to answer.
On question 603 we wrote "There are some contradictory issues involved in this question, such as the obligation to answer kadish, kedusha and amen. As opposed to the principle of “osek bemitzva potur min hamitzva” since one learning Torah is already complying with a great mitzvah that should exempt him from having to do another.
Betoroso Yehegeh (3: 3 p. 73-75) quotes Horav Chaim Kanievsky Shlit”a that although one is not obligated to listen to a baal tefilah once he has already completely finished davening, if he does hear kadish or kedusha he has to answer. This is similar to interrupting his learning in order to comply with any passing mitzvah that cannot be observed latter. Pischei Teshuva (O.H. 124: 5) rules that one does not answer Baruch Hu Ubaruch Shemo while learning, but although there are dissenting opinions we must answer omen. Rivavos Ephraim (O.H. 15) quotes contradicting opinions; Horav Eliashuv’s Zt”l rules that one need not answer omen in the middle of learning while Horav Moshe Feinstein Zt”l disagrees.
When listening to an ongoing tefilah while learning in an adjacent room, Teshuvos Vehanhogos (O.H. 5: 23) opines that although no transgression was incurred by not answering a dovor shebek’dusha while in another site, there still remains a positive mitzvah to answer if you hear. However, being occupied with Torah learning will exempt him the from having to answer.
When a group is involved in Talmud Torah d’rabim, the learning of many is more significant (Remoh O.H. 106: 2, in regards to reading of the Shema) See also Igrois Moishe (O.H. 3:83) that the shiur attendants do not have to recite the thirteen middos together with the minyan.
However, Betoroso Yehegeh (ibid.) quoting again Horav Chaim Kanievsky Shlit”a mentions that if the group hears they have to answer even omen, nevertheless they should concentrate in the shiur and then they don’t have to reply.
Horav Shlomo Miller’s Shlit’a opinion is similar. If one does hear the kadish, kedusha, and borchu recitation while learning he has to answer. In hearing kedusha only kadosh, boruch kevod and imloch need be answered. Saying omen is restricted to having heard the brocho or at least knowing on what he is saying omen".
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a
Important Numbers
