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Paper 12. Techniques for obtaining subjective response to vertical vibration
616
HUMAN
RESPONSE
TO VIBRATION
measurement procedures to the simulator motion settings and to determine the scatter among the ride index values. The best ride quality measurement procedure is that for which the scatter is smallest. Pilot experiments have been performed with recordings of 19 passenger rail car ride motions and a panel of four subjects. The application of several ride quality measurement procedures is discussed. Topics: Subjective Assessment (Intensity Matching); Complex Vibration (Various). M. J. Clarke and D. J. Oborne. Paper 12. Techniques for obtaining subjective response to vertical vibration. (20 pages, 13 figures, 3 tables, 13 references) Authors’ Conclusions edited by M. J. G. Experiments are described which were designed to test the efficiency of methods which could be used to obtain human response to vibration inputs, particularly in passenger vehicle situations. The rating-line method, which has been found to be one of the most easily used in field situations, was used to generate equal sensation contours whose shapes matched those obtained by other methods. The numerical values of line ratings have not, so far, been linked directly with numerical estimates of intensity obtained by, for example, magnitude estimation methods. The use of magnitude estimation techniques was examined. It was found that for situations where they could be used the methods of halving and doubling gave consistently different results with higher exponents for a power law expression than those provided by magnitude estimation. From an engineering point of view the indication is that magnitude estimation results are probably not conservative and should, therefore, be viewed with caution. Topics : Subjective Assessment (in General). N. C. Duncan and H. W. Conley. Paper 13. Demographic and psychological variables affecting test subject evaluations of ride quality. (35 pages, 24 figures, 8 tables, 10 references) Authors’ Conclusions edited by M. J. G. Two experiments were conducted to determine whether age, sex, and/or flight experience, along with other demographic and attitudinal variables, in addition to anxiety levels, play a significant role in influencing a person’s “comfort rating” of typical STOL aircraft motions. The only primary subject variable to significantly influence mean comfort ratings was the sex of the subject. However, this was only found in one study and at low vibration levels. This result could indicate that males are more sensitive to low vibration levels, whereas females are more tolerant of these same motions. It is possible that interactions exist between the demographic variables and it is recommended that factors such as education, occupation and income should not be neglected when selecting subjects for ride quality studies. There was a significant correlation between attitude toward flying and mean comfort rating which may indicate that those subjects who have a positive attitude were more tolerant of typical STOL aircraft motion than those having negative attitudes towards flying. There is an indication that a person’s anxiety level at the time of flying, that is, anxiety generated as a result of being in an aircraft, affects his mean comfort rating of the aircraft motion. Topics: Subjective Assessment (in General); Subject Type (Ages, Sex, Other). Note: Copies of all papers included in this section will be found in the Human Response to Vibration Literature Collection at the Institute of Sound and Vibration Research, The University of Southampton. The papers may be used by persons visiting the Institute and for a small charge photocopies of them can usually be provided by post. Contributions to the Literature Collection are requested from relevant research groups. They should be sent to Dr M. J. Grifin, Human Factors Research Unit, Institute of Sound and Vibration Research, University of Southampton, Southampton SO9 5NH, England.
HUMAN
RESPONSE
TO VIBRATION
measurement procedures to the simulator motion settings and to determine the scatter among the ride index values. The best ride quality measurement procedure is that for which the scatter is smallest. Pilot experiments have been performed with recordings of 19 passenger rail car ride motions and a panel of four subjects. The application of several ride quality measurement procedures is discussed. Topics: Subjective Assessment (Intensity Matching); Complex Vibration (Various). M. J. Clarke and D. J. Oborne. Paper 12. Techniques for obtaining subjective response to vertical vibration. (20 pages, 13 figures, 3 tables, 13 references) Authors’ Conclusions edited by M. J. G. Experiments are described which were designed to test the efficiency of methods which could be used to obtain human response to vibration inputs, particularly in passenger vehicle situations. The rating-line method, which has been found to be one of the most easily used in field situations, was used to generate equal sensation contours whose shapes matched those obtained by other methods. The numerical values of line ratings have not, so far, been linked directly with numerical estimates of intensity obtained by, for example, magnitude estimation methods. The use of magnitude estimation techniques was examined. It was found that for situations where they could be used the methods of halving and doubling gave consistently different results with higher exponents for a power law expression than those provided by magnitude estimation. From an engineering point of view the indication is that magnitude estimation results are probably not conservative and should, therefore, be viewed with caution. Topics : Subjective Assessment (in General). N. C. Duncan and H. W. Conley. Paper 13. Demographic and psychological variables affecting test subject evaluations of ride quality. (35 pages, 24 figures, 8 tables, 10 references) Authors’ Conclusions edited by M. J. G. Two experiments were conducted to determine whether age, sex, and/or flight experience, along with other demographic and attitudinal variables, in addition to anxiety levels, play a significant role in influencing a person’s “comfort rating” of typical STOL aircraft motions. The only primary subject variable to significantly influence mean comfort ratings was the sex of the subject. However, this was only found in one study and at low vibration levels. This result could indicate that males are more sensitive to low vibration levels, whereas females are more tolerant of these same motions. It is possible that interactions exist between the demographic variables and it is recommended that factors such as education, occupation and income should not be neglected when selecting subjects for ride quality studies. There was a significant correlation between attitude toward flying and mean comfort rating which may indicate that those subjects who have a positive attitude were more tolerant of typical STOL aircraft motion than those having negative attitudes towards flying. There is an indication that a person’s anxiety level at the time of flying, that is, anxiety generated as a result of being in an aircraft, affects his mean comfort rating of the aircraft motion. Topics: Subjective Assessment (in General); Subject Type (Ages, Sex, Other). Note: Copies of all papers included in this section will be found in the Human Response to Vibration Literature Collection at the Institute of Sound and Vibration Research, The University of Southampton. The papers may be used by persons visiting the Institute and for a small charge photocopies of them can usually be provided by post. Contributions to the Literature Collection are requested from relevant research groups. They should be sent to Dr M. J. Grifin, Human Factors Research Unit, Institute of Sound and Vibration Research, University of Southampton, Southampton SO9 5NH, England.