There are two blessings recited before the shofar is sounded. The first is related to the mitzvah (the requirement or commandment) to hear the sound of the shofar. The second is the traditional blessing said to celebrate a special occasion.
The first blessing is:
Baruch ata Adonai Eloheinu melekh ha-olam asher kidshanu b’mitzvotav v’tzivanu lishmoa kol shofar.
Blessed are You, Ruler of the World, who has made us holy with commandments, and who has commanded us to hear the voice of the shofar.
The second blessing is:
Baruch ata Adonai Eloheinu melekh ha-olam shehecheyanu v’kiyimanu v’higiyanu lazman ha-zeh.
Blessed are You, Ruler of the World, for giving us life, for sustaining us, and for enabling us to reach this season.