Directivity Patterns for Room Acoustical Measurements and Simulations

The acoustics of rooms can be objectively described by the room impulse responses obtained for given transfer paths using measurement or simulation. In practice, the directionally dependent behavior of sources and receivers is often disregarded and thus assumed to be of omnidirectional type. In reality, however, these sources and receivers have specific directivity patterns, which are reported to induce audible differences. In this work a methodology to capture, analyze and process directivity patterns of sources and receivers is described. With the help of surrounding spherical microphone and loudspeaker arrays these directivity patterns are measured to be used in room acoustic applications. Room impulse responses with respect to specific directivity patterns can be realized using compact loudspeaker arrays with known directivity. Applying the results of directivity superposition to the set of measured room impulse responses, the acoustics for specific directivity patterns are found. Using a simulation of the room instead, source and receiver directivity patterns can be included in both wave based and particle based methods. The results of this work facilitate more authentic descriptions of room acoustics for specific source and receiver directivity patterns.