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Psychophysical scaling of human response to whole-body vertical vibration
Jottrnal of Sotmd and Vibration (1973) 31(4), 501-504
HUMAN
RESPONSE TO
VIBRATION
REVIEWS AND ABSTRACTS
Prepared by M. J. Griffin and J. Griffin, Httman Factors Research Unit, hlstitute of Sound attd Vibration Research, University of Southampton, Southampton S09 5NH, England ABSTRACTS The 1973 meeting of the United Kingdom Informal Group on Human Response to Vibration was held at the University of Salford from 17th to 19th September. This month's section of abstracts is devoted solely to a selection of the twenty papers presented at that Conference. A. J. Jones 1973. Paper presented at United Kingdom hformal Group Meeting on Human Response to Vibration, Unir'ersity of Salford, 17th-19th September, 1973. A scale of human reaction to whole body, vertical, sinusoidal vibration. (7 pages, 2 figures, 2 tables, 5 references)
Summar), by M.J.G. This paper describes the use of a relative intensity estimation procedure carried out in order to determine whether subjects are abIe to consistentlyjudge the magnitude of one vibration stimulus in relation to another. From the results a scale ofsubjective response to vibration intensity has been developed. It was found that human reaction could be adequately described by a growth function of the form
y = kX o.93, where Y is the subjective magnitude of vibration, X is the objective magnitude of vibration acceleration and k is a constant. This type of function is commonly referred to as the Stevens Power Law, since S. S. Stevens has proposed its existence for several sensory modalities. The value of the exponent at 0.93 represents that found by pooling all the data for 30 men and 30 women who all adopted an unrestrained sitting position and carried out the experiment at several frequencies of vibration in the range 5 to 80 Hz. The results for each vibration frequency employed could also be satisfactorily described by a power law growth function. Generalized vibration contours and a vibration magnitude scale ha~'e been derived from the data. The author anticipates that when the mechanism of subjective addition of frequency components in a complex vibration is understood these scales may be used to give an overall "vibration level index". Topics: Subjective Assessment (hltensity Matchhtg, )~fagnitttde Esthnation) L. C. Fothergill 1973 Paper presented at United Kingdom htformal Group Meethzg on Htonan Response to Vibration, University of Salford, 17th-19th September, 1973. Psychophysical scaling of human response to whole-body vertical vibration. (9 pages, 3 figures, 2 tables, 6 references)
Author's Abstract. The vibration in many types of transport can be approximated by several sinusoidal components combined with a low level random vibration. A method of assessing the subjective human response to such a vibration has been determined by way of five experiments. In outline, the complex vibration signal is fed through a narrow band analyzer and 501
HUMAN RESPONSE TO VIBRATION
h of the "i" components is equated to an equivalent level,B,, of I0 Hz sinusoidal vibration. 9se equivalent levels are found from equal sensation contours. The level, Ec, of I0 Hz .jectivelyequivalent to the complex vibration is calculated from Ec = V'~,E~. Whether or this level is acceptable for any particular situation is determined by consulting tables ived from fieldmeasurementsor simulator studies. It is to be expectedthat differenttables 9be required for different environmental circumstances. "his method is equivalentto the use of a weighting network and so may be taken to support weighting filter technique described in the proposals of the Intcrnational Standards ,,anisation. 9ics: Subjective Assessment (h~tensity Matching); Complex Vibration (~Iultiple Fre9I z c y )
~. Hempstock and D. J. Saunders 1973 Paper presented at United Kingdom hzformal Group ethlg on Iluman Response to Vibration, University of Salford, 17th-19th September, 1973. ~ss-modality determination of the vibration growth function. (7 pages, 1 figure, 4 tables, :ferences)
:hor's Conchtsions. A cross-modality technique where subjects were required to match the sations of noise and vibration has been used to establish a growth function for vibration. :as been shown that the form of this function is greatly influenced by which stimulus serves :he dependent and which as the independent parameter. If a growth function of the form Kq~" is assumed then the value of the index m was found to vary by a factor of two dependon the matching procedure. :
pics: Subjective Assessment (Magnitude Esthnate, Cross Modality) H. Rance and G. R. Barnes 1973 Paper presented to UnitedKingdonz h~formal Group Meeton Human Response to Vibration, University of Salford, 17tl:-19th September, 1973. msmission of angular acceleration to the head in the seated human subject. (10 pages, gures)
thor's Abstract. Vibration is an environmental stress relevant to aircraft operation par~larly in high-speed low-level flight when imposed head movements may influence aircraft atrol. Little information is available concerning head movements occurring in response to oscillating input to the seated or standing subject. ~. preliminary investigation was undertaken to ascertain the type and magnitude of head wements which occurred when an unrestrained seated subject was oscillated in yaw. Head wements were demonstrable in all three rotational axes. Movement in pitch showed fre~ncy doubling when the yaw input was in the frequency range 2--4 Hz. An attempt to 9lain these phenomena in anatomical and mechanical terms is being made. Further investi:ion of a restrained body subjected to oscillation in other rotational axes is in progress to rify the type and cause of the observed movements. pics: Non-vertical Vibration (Yaw); Biodynamics (General) . J. Griffin 1973 Paper presented at United Kingdom h~formal Group Meethlg on IIuman ~sponse to Vibration, University of Salford, 17th-19th September, 1973. Whole-body vibra.n levels affecting visual acuity. (10 pages, 5 figures, 1 table, 2 references)
fthor's Abstraci. A visual task has been devised to investigate the effects of whole-body )ration on eye-movements and vision. This task is the detection of retinal blur and is conlered to be as sensitive as any suitable alternative measure of visual acuity.
HUMAN
RESPONSE TO
VIBRATION
REVIEWS AND ABSTRACTS
Prepared by M. J. Griffin and J. Griffin, Httman Factors Research Unit, hlstitute of Sound attd Vibration Research, University of Southampton, Southampton S09 5NH, England ABSTRACTS The 1973 meeting of the United Kingdom Informal Group on Human Response to Vibration was held at the University of Salford from 17th to 19th September. This month's section of abstracts is devoted solely to a selection of the twenty papers presented at that Conference. A. J. Jones 1973. Paper presented at United Kingdom hformal Group Meeting on Human Response to Vibration, Unir'ersity of Salford, 17th-19th September, 1973. A scale of human reaction to whole body, vertical, sinusoidal vibration. (7 pages, 2 figures, 2 tables, 5 references)
Summar), by M.J.G. This paper describes the use of a relative intensity estimation procedure carried out in order to determine whether subjects are abIe to consistentlyjudge the magnitude of one vibration stimulus in relation to another. From the results a scale ofsubjective response to vibration intensity has been developed. It was found that human reaction could be adequately described by a growth function of the form
y = kX o.93, where Y is the subjective magnitude of vibration, X is the objective magnitude of vibration acceleration and k is a constant. This type of function is commonly referred to as the Stevens Power Law, since S. S. Stevens has proposed its existence for several sensory modalities. The value of the exponent at 0.93 represents that found by pooling all the data for 30 men and 30 women who all adopted an unrestrained sitting position and carried out the experiment at several frequencies of vibration in the range 5 to 80 Hz. The results for each vibration frequency employed could also be satisfactorily described by a power law growth function. Generalized vibration contours and a vibration magnitude scale ha~'e been derived from the data. The author anticipates that when the mechanism of subjective addition of frequency components in a complex vibration is understood these scales may be used to give an overall "vibration level index". Topics: Subjective Assessment (hltensity Matchhtg, )~fagnitttde Esthnation) L. C. Fothergill 1973 Paper presented at United Kingdom htformal Group Meethzg on Htonan Response to Vibration, University of Salford, 17th-19th September, 1973. Psychophysical scaling of human response to whole-body vertical vibration. (9 pages, 3 figures, 2 tables, 6 references)
Author's Abstract. The vibration in many types of transport can be approximated by several sinusoidal components combined with a low level random vibration. A method of assessing the subjective human response to such a vibration has been determined by way of five experiments. In outline, the complex vibration signal is fed through a narrow band analyzer and 501
HUMAN RESPONSE TO VIBRATION
h of the "i" components is equated to an equivalent level,B,, of I0 Hz sinusoidal vibration. 9se equivalent levels are found from equal sensation contours. The level, Ec, of I0 Hz .jectivelyequivalent to the complex vibration is calculated from Ec = V'~,E~. Whether or this level is acceptable for any particular situation is determined by consulting tables ived from fieldmeasurementsor simulator studies. It is to be expectedthat differenttables 9be required for different environmental circumstances. "his method is equivalentto the use of a weighting network and so may be taken to support weighting filter technique described in the proposals of the Intcrnational Standards ,,anisation. 9ics: Subjective Assessment (h~tensity Matching); Complex Vibration (~Iultiple Fre9I z c y )
~. Hempstock and D. J. Saunders 1973 Paper presented at United Kingdom hzformal Group ethlg on Iluman Response to Vibration, University of Salford, 17th-19th September, 1973. ~ss-modality determination of the vibration growth function. (7 pages, 1 figure, 4 tables, :ferences)
:hor's Conchtsions. A cross-modality technique where subjects were required to match the sations of noise and vibration has been used to establish a growth function for vibration. :as been shown that the form of this function is greatly influenced by which stimulus serves :he dependent and which as the independent parameter. If a growth function of the form Kq~" is assumed then the value of the index m was found to vary by a factor of two dependon the matching procedure. :
pics: Subjective Assessment (Magnitude Esthnate, Cross Modality) H. Rance and G. R. Barnes 1973 Paper presented to UnitedKingdonz h~formal Group Meeton Human Response to Vibration, University of Salford, 17tl:-19th September, 1973. msmission of angular acceleration to the head in the seated human subject. (10 pages, gures)
thor's Abstract. Vibration is an environmental stress relevant to aircraft operation par~larly in high-speed low-level flight when imposed head movements may influence aircraft atrol. Little information is available concerning head movements occurring in response to oscillating input to the seated or standing subject. ~. preliminary investigation was undertaken to ascertain the type and magnitude of head wements which occurred when an unrestrained seated subject was oscillated in yaw. Head wements were demonstrable in all three rotational axes. Movement in pitch showed fre~ncy doubling when the yaw input was in the frequency range 2--4 Hz. An attempt to 9lain these phenomena in anatomical and mechanical terms is being made. Further investi:ion of a restrained body subjected to oscillation in other rotational axes is in progress to rify the type and cause of the observed movements. pics: Non-vertical Vibration (Yaw); Biodynamics (General) . J. Griffin 1973 Paper presented at United Kingdom h~formal Group Meethlg on IIuman ~sponse to Vibration, University of Salford, 17th-19th September, 1973. Whole-body vibra.n levels affecting visual acuity. (10 pages, 5 figures, 1 table, 2 references)
fthor's Abstraci. A visual task has been devised to investigate the effects of whole-body )ration on eye-movements and vision. This task is the detection of retinal blur and is conlered to be as sensitive as any suitable alternative measure of visual acuity.