- Report #: NT ACOU 116
- Approved: November 2004
This method specifies how to determine the noise emission characteristics of road vehicles to obtain input data to be used in prediction methods for road traffic noise.
Pass-by sound exposure due to individual road vehicles traveling at constant speed are measured one at a time in several microphone positions. All measurements and calculations are done in one-thirdoctave bands ranging from 25 Hz to 10 kHz.
The method gives an estimate of the acoustic impedance of the road surface. For each population of vehicles the method gives estimates of a weight function for the sub-sources in the vehicle model and the expected sound power.
Field of application
The method is applicable to all types of constant speed operating conditions and to all types of vehicles on all types of road surfaces provided that the measurement conditions are under control and reported.