The new European standard for qualifying added devices (invited lecture)

CEN (European Standard Committee) has developed a new standard for determining the intrinsic characteristics of sound diffraction of products to be added on the top of noise reducing devices. The test method prescribes measurements of the sound pressure level at several reference points near the top edge of a noise reducing device with and without the added device installed on its top. The effectiveness of the added device is calculated as the difference between the mean values with and without the added devices. No other national or international standard exists about this subject.