It is a positive Torah commandment to hear the Shofar blasts on the day of Rosh Hashanah, as the verse states, “It shall be a day of [Shofar] blasts for you.” One may not speak between the various sets of Shofar blasts and certainly not during the blasts themselves. The Poskim disagree regarding whether or not it is permissible to recite the order of confession (which is printed in most Rosh Hashanah prayer books). Maran Rabbeinu Ovadia Yosef zt”l rules that one may not recite this confessional prayer between the sets of the Shofar blasts, for this causes one to enter the realm of a blessing in vain and it becomes doubtful whether or not one must recite the blessing on the Shofar blasts again; even if one has customarily recited this confessional prayer in the past, one must discontinue this custom at once. Nevertheless, if one would like to read this confessional prayer with one’s eyes only and ponder it in one’s heart, this is indeed permissible between the sets of blasts; however, during the time the Shofar blasts are actually being sounded, one must sit silently and listen carefully to the Shofar blasts.
Women are exempt from hearing the Shofar blasts since this is positive, time-bound Mitzvah and women are exempt from such Mitzvot as we have discussed on several occasions. Nevertheless, it is customary that women act stringently and come to the synagogue to hear the Shofar blasts. A woman did not have the opportunity to come to the synagogue on the morning of Rosh Hashanah may indeed hear the Shofar blasts at home (or later on in the synagogue during the afternoon hours of Rosh Hashanah, as has become the prevalent custom in many synagogues). When one blows the Shofar for women, one may not recite the “Lishmo’a Kol Shofar” blessing since women are exempt from such positive, time-bound Mitzvot. There are some Ashkenazi women who customarily recite the blessing on the Shofar by themselves and they indeed have on whom to rely. Nonetheless, the one blowing the Shofar should not recite a blessing when blowing for women, even according to this opinion.
The Mitzvah of hearing Shofar blasts may be fulfilled throughout the entire day of Rosh Hashanah, beginning from sunrise until sunset. Therefore, if one would like to blow the Shofar for women, one may do so all day, until sunset.
We have a great rule that “Mitzvot require intention”, as we have discussed in a special Halacha. Thus, before hearing the Shofar blasts on Rosh Hashanah, one must pay attention and have in mind to fulfill the positive Torah commandment of hearing the Shofar blasts when hearing the sound of the Shofar.