Sensitivity of Seated Subjects to Low Frequency Random Vibrations in the Vertical Direction. Subjective Approach Using Vibrations Representative of Earthmoving Machines

Abstract

A study was conducted to compare various methods for evaluating complex vibrations. The two methods recommended by the Standard ISO 2631 were tested. A subjective equalization technique was used in which 10 seated subjects were asked to adjust the intensity of a test stimulus until they perceived a whole body sensation equivalent to a reference stimulus. The vibration stimuli were low frequency motions along the vertical axis and they were representative of earthmoving machines. They were compared to each other and to sinusoidal and third octave band random vibrations centred at the same frequencies. The results obtained indicate that the overall frequency weighting methods are the most appropriate for the evaluation of complex vibrations. The vertical weighting curve recommended by the Standard ISO 2631 produces suitable results.