Early reflection energy in concert halls: how much, how early, and from where (A)

Today, the importance of distributing early reflection energy to listeners and performers in concert halls is well understood and accepted—also among architects. Still, implementation in the practical design of a large hall is not easy, partly because we still have difficulties quantifying precisely the demands in detail (how much, how early, and from where) due to limitations in our acoustic knowledge—and often also due to little response from the clients regarding their preferences when decisions between alternative demands must be made. Therefore, in general it is up to the acoustician to decide how far to promote the good cause on the basis of his/her experience, taste, and talent in influencing the decision process. The aural presentation will focus on the current limitations in our knowledge regarding the musicians' need for early reflections, which is a special challenge in the design of terraced, ``surround'' concert halls. In the case of the listeners, knowledge has reached a much higher level, and recent results regarding how room shape influence the objective acoustic parameters monitoring the early energy will be presented.