During the brachas for megillah reading or during the brachos of tekios shofar in shul if there is a tzibbur, is the tzibbur required to/ or is it a minhag/ or no source for the tzibbur to stand for the brachos of kriyas megillah or tekiyas Shofar while the reader is saying the brachos out loud?
Machtzis Hashekel 690:1 says that since the one making the Bracha has to stand, therefore the one hearing the Bracha of Megila has to also stand from the Din of Shomai'a K'oneh שומע כעונה.
Shulchan Shlomo 690:1 says that it seems to him that the one hearing the Bracha of Megila should also be standing.
Kaf Hachaim 585:1:1 - towards end in discussing Tekiyas Shofar quoting many different sources, says that one should stand while hearing the Bracha of Tekiyas Shofar from the Din of Shomai'a K'oneh שומע כעונה. However he brings a dissenting view from the Ben Ish Chai that says it is not necessary to stand during the Brachos of Tekiyas Shofar.