1,152. Who Must Hear the Shofar?

Hilchos Shofar, Succah v’Lulav 1:8

If a person blows shofar in a pit or a cave, anyone standing in the pit or the cave fulfills their obligation. Of those outside, if they hear the sound of the shofar, they fulfill their obligation but if they hear the sound of an echo, they do not. The same is true of one who blows shofar into a large barrel; if he hears the sound of the shofar, he fulfills his obligation but if he hears an echo, he does not.

Hilchos Shofar, Succah v’Lulav 2:1

Everyone is required to hear the shofar blown: Kohanim, Leviim, Yisroelim, converts and freed servants. Women, (unfreed) servants and minors are not so obligated. One who is half-servant and half-free is obligated, as is a hermaphrodite and a person of indeterminate gender.