Reflectance Profile Method for the Acoustical Design of Buildings

The acoustic character of interior enclosed spaces is typically described by Reverberation Time (RT-60) and presented as a single value based on the total number of sabins in a spatial volume. When a series of reverberation times are calculated at frequency band centers well-accepted terminology can be applied for describing the space for conditions where reverberation is missing, prevalent, or excessive. Therefore, reverberation time provides a spatial description but little about the material properties of room surfaces that create the condition. This paper presents a simple methodology for calculating the Reflectance Profile of a space. Examples of typical spaces such as hotel rooms and elementary school classrooms are included to demonstrate its utility as a design tool. The Glass House, a proposed music hall entirely enclosed in glass, is also included to indicate how the Reflectance Profile can provide an easy, understandable means of identifying corrective measures that should be employed during design to avoid frequency imbalance. It has led to the study of triangular non-damping reflective panels for use in the Glass House.