Vibro-acoustic analysis procedures for the evaluation of the sound insulation characteristics of agricultural machinery cabins

Over the last few years, customer demands regarding acoustic performance, along with the tightening of legal regulations on noise emission levels and human exposure to noise, have made the noise and vibration properties into important design criteria for agricultural machinery cabins. In this framework, both experimental analysis procedures for prototype testing as well as reliable numerical prediction tools for early design assessment are compulsory for an efficient optimisation of the cabin noise and vibration comfort. This paper describes an experimental procedure for the in-situ assessment of the air-borne sound insulation characteristics of a cabin using a two-microphone sound intensity probe. In addition, several numerical approaches, which are based on the finite element and boundary element method, are discussed in terms of their practical use for air-borne sound insulation predictions. To illustrate the efficiency and reliability of the various vibro-acoustic analysis procedures, all experimental and numerical procedures have been applied and evaluated for the case of a cabin scale model.