Subjective response to combined noise and vibration: summation and interaction effects

Laboratory simulations of the noise and vibration in buildings caused by nearby railways have been used to study the effects of simultaneous noise and vibration on subjective responses. Twenty-four subjects attended three sessions during each of which they were presented with six levels of noise combined with six magnitudes of vibration, in all 36 combinations. In Session A the assessment of vibration in the presence of noise was investigated: subjects used the method of magnitude estimation to assign values to indicate their assessment of vibration. In Session B the assessment of noise in the presence of vibration was investigated: values were assigned to indicate assessment of noise. In Session C the combined effects of noise and vibration were investigated: values were assigned to indicate reaction to the combination of the two stimuli. The results suggest that, within the range of magnitudes of stimuli investigated, vibration does not influence the judgement of noise but the judgement of vibration may be increased or reduced by the presence of noise, depending on the relative magnitudes of the two stimuli. The results indicate that although there may be an interaction between the two stimuli, the effect may not be simple or consistent. A reasonable approximation to the total annoyance caused by a combination of noise and vibration can be determined from a summation of the effects of the individual stimuli.