The following paper discusses elements such as room size, room composition, room shape, and the location of the listener
and sound source, when designing theater acoustics. Finding the ultimate impulse response with testing is also discussed. From the paper: "It has been considered that gross errors in concert hall design are rarely due to use of the wrong absorption
coefficients, as most of the materials used are highly reflective. A theatre audience first hears sound generated from the source. Then they will hear attenuated bounces of sound off the walls. The sound is again and again reflected off the walls, resulting in total
reverberation of the sound. In a large room such as a theatre, reverberation time can be as long as four seconds."