Yosef Karo

“ Similarly, one who hears somebody sounding the shofar without intention does not fulfill their obligation. Similarly, one who sounds the shofar for music and does not intend for the soundings to fulfill the obligation does not fulfill their obligation. If the hearer has intention and the blower does not have intention, or the blower has intention and the hearer does not have intention, the obligation is not fulfilled until both the hearer and the sounder have intention. ”

“ Similarly, somebody who has already fulfilled his obligation can sound a shofar to fulfill women's obligations. However, they should not make a blessing, nor should others make a blessing for them. Rem"a: Given that the custom is that women bless on time-bound commandments, they also can bless for themselves here. However, others should not bless on behalf of women if the blower has already fulfilled his obligation and is just blowing for women. ”