Nowadays the protection of human life is extremely important, and for this purpose the vehicles must go through a homologation process before the introduction to market. If we look at the acoustical requirements, one of the most important test procedures is the Pass-by Noise (PBN) measurement, which defines the noise emission limit value, when the observer stands beside the vehicle passing him by. There are two versions: Exterior (or Outdoor) and Indoor (or In-room) Pass-by Noise (IPBN) measurement. Former is presently the only accepted method for homologation; however, environmental and weather conditions could strongly influence its feasibility. For this reason, IPBN got into focus, with better suitability for development purposes and the prospect, that it will be accepted later for the homologation process too. This paper focuses on the IPBN method: gives an overview on the setup and presents the details of a realized test-measurement campaign. Beside the 2 most important points: the measuring room and the position of the sensors, the measurement devices, vehicle location and connection to measurement system, the measuring program and the whole process are presented together with some preliminary results related to different characteristics of the vehicle.

In vehicles there are 3 main noise sources: powertrain noise (e.g. engine, gear engagement or exhaust noise), aerodynamic noise (or wind noise), and the noise from the tire-road contact. The first two are traditionally in the primary focus of vehicle manufacturers, however, due to both the already made powerful developments and the spreading of electric vehicles, the rolling noise is gaining more and more attention during the vehicle development process. There are two major influencing factors of this noise source: tire (geometrical and material) characteristics and road (surface) characteristics. The separation of their contribution is not straightforward, investigated rarely, and the requirements of homologation standards do not expect it neither. However, if one would like to meet the new vehicle pass-by noise regulations, it is more and more inevitable to have a sophisticated break-down of rolling noise. A straightforward solution is the usage of a one-wheel testbench developed directly for acoustical measurements. Such design process is presented in this paper, where the most important requirements are: enabling the users to compare tires from acoustical aspect under totally objective conditions, modelling the typical conditions of vehicles and ensuring data for rolling noise simulations. One further functionality of the testbench is to reproduce the real rolling noise by mounting realistic road surface sections onto the superficies.