A special frequency weighting has been found useful for certain measurements of aircraft noise. BS 5721 has been specially prepared for use in conjunction with ISO standards on aircraft noise measurements.
BS 5721 defines a weighting characteristic which is designated D for the above-mentioned purpose.
BS 5721 on frequency weighting for aircraft noise measurement is useful for:
Adherence to BS 5721 can ensure minimum variations in measurement results obtained using equipment of various makes and models.
Special equipment that has a D-weighting characteristic as defined in BS 5721 and otherwise complies with IEC Publication 179, Precision Sound Level Meters, has been accepted for the measurement of aircraft noise.
BS 5721 provides you with the guidance on the characteristics for frequency D weighting.
Compliance with BS 5721 can be beneficial for quality control purposes to ensure that acoustical disturbances are kept to a level that does not in any manner impair the performance and efficiency of the aircraft when in operation.