Psychoacoustic characterisation of the noise at the operator position of a compact loader during real working conditions

Current standards on noise exposure for earth-moving machine workers require to measure the sound pressure level at the operator station while the machine is simulating a defined working cycle without using any kind of material. This approach could really underestimate the level of risk for the operator because leading to noise values lower than the actual ones. In addition, recent research showed that different noise sounds, although having the same A-weighted level, may have quite different perceptual effects. In this respect a research is in progress aiming at characterising the noise at the operator station of compact loaders during actual working conditions. Binaural noise signals were recorded while different loaders were performing a defined working cycle including different phases and the use of two different kinds of material. The recorded signals were analysed in terms of physical and psycho-acoustic parameters and used in subjective listening tests with the purpose to identify the set of parameters which affect the auditory perception of these signals with respect to undesired conditions of comfort.