Influence of sound source positions and spatial sampling in the measurement of façade sound insulation with large receiving rooms

At present, ISO 16283-3 describes procedures for the measurement of façade sound insulation for room volumes up to 250m3. However, in some buildings (e.g. universities, schools, offices) it is common to find larger room volumes, up to 500 m3, where it is necessary to measure the façade sound insulation to check conformity with National regulations or guidance. This paper assesses the façade sound insulation in a 460m3 university lecture room where the tested façade is half the length of the other dimension of the room. This leads to the possibility of sub-dividing a large receiving room volume into smaller sub-volumes. The results indicate that the sub-volume, which is farthest away from the shortest façade, can be neglected without significantly changing the façade sound insulation. This could potentially reduce the measurement time for façade sound insulation measurements on site.