Last Updated: 20050817, mei
Friday, October 7, 9:00 am — 12:00 pm
T1 - The Acoustics and Psychoacoustics of Loudspeakers in Small Rooms: A Review
Floyd Toole, Harman International Industries, Inc. - Northridge, CA, USA
The physical measures by which acousticians evaluate the performance of rooms have evolved in performance spaces—concert halls, opera houses, and auditoria. They rely on a set of assumptions that become progressively less valid as spaces get smaller and more acoustically absorptive. In live performances, sound sources radiate in all directions and the room is a part of the performance. In sound reproduction, loudspeakers tend to exhibit significant directivity, and what we hear should ideally be independent of the listening room. What, then, should we measure in small rooms? What configuration of loudspeakers and acoustical treatment is appropriate for multichannel audio reproduction? To what extent can we "eliminate" the room? Or, do we need to? Is there a point beyond which the human hearing system is able to adapt to the listening space—hearing "through" the room and "around" the reflections to accurately perceive the source? A certain amount of the right kind of reflected sound appears to enhance the music listening experience and, interestingly enough, to improve speech intelligibility. In this tutorial we review some of the basic science, using existing knowledge to provide guidance for choosing and using loudspeakers in rooms, and pointing out gaps in our knowledge— subjects for future research.