Analysis of the effects of uneven sound coverage over a facade during a sound insulation test according to the international standard ISO 16283-3

To make the method consistent, the international standard establishes some constraints, trying to minimize the variation of sound pressure level on the facade. This variation is caused by the directivity of the loudspeaker and the distance from the loudspeaker to the facade, causing an uneven sound coverage over the facade. This paper analyzes and quantifies the solitary influence of facade coverage on the sound insulation determinations in relation to the location of the facade elements. In addition to other influences, the specific location of a small air inlet on a facade can alter the results by up to 4 dB, even if the sound coverage complies with the requirements established by the international standard. Finally, an alternative measurement setup is discussed that aims to minimize the negative effect of this phenomenon in an attempt to increase the consistency of the method.