The Rambam writes in eight places that the mitzvah is to listen, not to blow the shofar. The Semag, Sheiltot, and Rosh hold that the mitzvah is to blow the shofar. The Avnei Nezer: if the mitzvah is to hear it, why can’t you be yotzei if a minor blows the shofar; if the mitzvah is to blow it, why can’t you blow it into a pit (where you can’t hear it)?
Shiur provided courtesy of Torah Anytime