THE EFFECT OF EXPOSURE TIME ON THE ACUTE EFFECTS OF WHOLE-BODY VIBRATION. I. A REVIEW OF AVAILABLE RESEARCH EVIDENCE. II. AN EMPIRICAL STUDY WITH RESPECT TO SUBJECTIVE EFFECTS

Exponeringstidens betydelse för de akuta effekterna av helkroppsvibrationer: I En forskningsöversikt. II En empirisk prövning med avseende på subjektiva besvär

I: a review is given of the research concerning duration effects on comfort, performance, physiological and biomechanical responses to whole-body vibration. It is concluded that there is no clear evidence for the existence of an increasing effect as a function of exposure-time although occasional studies have shown effects on biomechanical parameters, emg and auditory evoked potentials. Methodological shortcomings which might have contributed to the absence of duration effects in the comfort and performance studies are discussed. II: the method of "cross-modality matching" is proposed as a possible solution of some of the methodological problems in connection with studies of changes of the subjective effects during a prolonged exposure. Two experiments were performed with this method. In both the ss' task was to adjust a broadband noise to the level where it gave rise to the same degree of discomfort as a vibration. The sound levels were transformed into vibration levels by means of individually determined noise-vibration functions. In the first experiment which primarily was aimed at testing the methodology, the development of discomfort during a 16 minutes exposure to a random vertical vibration with a 6,3 hz resonance was studied. In the second experiment the exposure time was prolonged to 64 minutes and a 3,1 hz vibration plus a control condition were added. Both vibrations were recorded in industrial trucks. The experiments showed that the sound level settings increased as a function of exposure time. Control measurements showed that this could not be explained as a result of a lowered sensitivity to the noise. The increase, expressed in log acceleration, was a linear function of log exposure-time and it is therefore concluded that the results from studies of shorter exposure periods might be extrapolated up to at least one hour. Although the method probably leads to an underestimation of the increase, the experiments confirm that the increase is overestimated by iso 2631. There was no effect of frequency in this respect. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9174641638
• Corporate Authors:

  National Board of Occupational Safety and Health

  S-171 84 Solna,   Sweden 
• Authors:
  • Kjellberg, Anders
  • Wikström, Bengt Olav
  • Dimberg, Ulf
• Publication Date: 1983

Language

• Swedish

Media Info

• Features: Figures; References;
• Pagination: 56 p.
• Serial:
  • Publication of: National Board of Occupational Safety and Health
  • Publisher: National Board of Occupational Safety and Health
  • ISSN: 0346-7821

Subject/Index Terms

• TRT Terms: Anthropometry; Anthropometry; Behavior; Biophysics; Comfort; Crash exposure; Human factors; Noise; Perception; Simulation; Test procedures; Time; Tolerance (Physiology); Trucks; Vibration
• Uncontrolled Terms: Exposure
• ITRD Terms: 9001: Behaviour; 9138: Comfort; 2055: Human body; 2051: Human tolerance; 1236: Lorry; 2229: Perception; 9103: Simulation; 6748: Sound; 6288: Test method; 5414: Time; 5558: Vibration
• Subject Areas: Environment; Highways; Motor Carriers; Safety and Human Factors; Vehicles and Equipment; I92: Vehicle Comfort;

Filing Info

• Accession Number: 00381120
• Record Type: Publication
• Source Agency: Swedish National Road and Transport Research Institute (VTI)
• ISBN: 91-7464-163-8
• Report/Paper Numbers: 1983:9 Monograph
• Files: ITRD, TRIS
• Created Date: Apr 30 1984 12:00AM