The blowing of the shofar – a mitzva
There is a minhag to blow the Shofar throughout the month of Elul as a warning and reminder to do teshuva. However, the real torah obligation and positive commandment to blow the shofar is on Rosh Hashana. This is seen in one of the names for Rosh Hashana – Yom Terua, a day of the blowing of the terua sound. The Gemora Rosh Hashana says that it says in the Torah three times to blow a terua and each time it is accompanied by the sound of tekia before and after it, making a total of nine sounds. However, since we are in doubt as to what is the true terua sound we blow all the three possible combinations bringing the total to thirty sounds. These are blown straight after reciting the brocha and are the sounds the women listen to. The remaining seventy sounds is a minhag.