scope:

This International Standard describes a test method for measuring in situ the sound absorption coefficient of
road surfaces for frequencies ranging from 250 Hz to 2 500 Hz under normal incidence conditions.
The test method is intended for the following applications:
. determination of the sound absorption coefficient of dense road surfaces (and if of interest also the
complex acoustical impedance);
. determination of the sound absorption properties of test tracks according to ISO 10844 or other similar
standards and test surfaces defined in national and international type approval regulations for road
vehicles and vehicle tyres;
. comparison of the sound absorption coefficient of a road surface after completion with the designspecifications.