Building acoustics is the science of controlling noise in buildings. This includes the minimization of noise transmission from one space to another and the control of the characteristics of sound within spaces themselves.
Building acoustics are an important consideration in the design, operation and construction of most buildings, and can have a significant impact on health and wellbeing, communication and productivity. They can be particularly significant in spaces such as concert halls, recording studios, lecture theatres, and so on, where the quality of sound and its intelligibility are very important.
The requirements for the loudspeaker systems used for laboratory measurements are found in Annex C of ISO 140/3.
For field measurements the requirements are found in Annex A of ISO 140/4.
For Reverberation Time measurements the requirements are found in Annex A of ISO 3382. These Standards specifies the direction as well as the internal differences for the individual frequency bands in the noise spectrum.