What does architectural acoustics mean?

architectural acoustics is the branch of science that deal with the sound control in the building ...it deals with hw the sound can be trapped inside of the building or not, like in amphitheater in that the sound is trapped in it enabling the audience to hear what the person on stage is saying with out the use of microphone ...n viceversa is done in some place so as not to get the sound trapped as it can some time effect the building.