Videotape demonstrations of auditorium design principles using acoustic scale models

Abstract

A videotape demonstration was developed to illustrate acoustical design principles for auditoria to undergraduate architecture students. An acoustical scale model of an auditorium was constructed with removable walls, floor, and ceiling. Starting with a microphone in free space, an enclosure is built in steps around the source and receiver. An echogram is recorded at each step so students can see the effect of increased enclosure on the sound that arrives at the listener's position. Theater seating, various quantities of absorbent material, acoustically shaped ceiling panels, and diffusing elements are added to the enclosure as the demonstration progresses. Echoes, excessive loudness, flutter, and other basic acoustical problems and their solutions are presented. The demonstrations show changes in the impulse response of the room as changes are made in the shape and volume of the room. It serves as an introduction to acoustical modeling and auditorium design for the students.