Unfortunately the air-conditioning systems in many buildings are designed inadequately from an acoustical point of view. Too often one still finds a conference room where the speaker is almost "drowned" by a noisy air-conditioning system or a hotel bedroom where the air conditioner must be turned off in order to get a decent night's sleep. This is surprising since noise control approaches are well known and if the basic guidelines given in Chapter 35 of the 1973 ASHRAE HANDBOOK Systems Volumel are followed, air-conditioning systems which are quite adequate acoustically will be obtained !or little additional cost. One must conclude that either air-conditioning engineers do not read the advice given in Chapter 35 and/or the contractors or building owners are not familiar with or interested in the possibility of providing a suitable acoustical environment in a building.

The purpose of this symposium is to describe how a proper acoustical-environment in a building can be obtained. Besides introducing the next four papers in this symposium, this paper will define the acoustical definitions, notation and symbols used in the following papers.