PREDICTION OF IN-CAB NOISE EXPOSURE OF DRIVERS

The noise levels within truck cabs and the noise exposure of drivers were measured during commercial payload runs with an instrument of special design. Sound levels were continuously recorded within both ears of the driver and at the centre of cab station. It was found that the sound levels within the ears were in most cases significantly higher than those at the centre of cab station and that the greatest exposure existed during freeway driving. A relatively simple formula was developed for the prediction of noise exposure. This paper presents details of a study performed to determine the potential noise exposure of truck drivers running heavy vehicles under commercial operating conditions and, ultimately, to determine if a simple and inexpensive noise prediction method can be developed for such operations. By means of this method the noise exposure can be calculated thus eliminating the need for the far more expensive and inconvenient instrumentation monitoring procedure. An earlier paper (see reference) describes in detail how the results presented in this paper were obtained. Therefore only a short summary of the measurement procedure and the general considerations, which dictated the use of this method, will be given here.