The European Commission requires noise reductions of up to 5dB in the permitted levels from vehicles by 1995. The author reviews the problems facing manufacturers and discusses current research. Noise emission is complicated by the lack of clearly defined international standards for its measurement, and pollution depends upon noise quality as well as loudness. Factors such as temperature, air pressure and the type of road surface have a large effect on vehicle noise levels. Tyres now contribute half the noise produced by cars. Porous tarmac surfacing could reduce emission by up to 4dB. Attempts are being made to standardise the road surface used for noise tests. Software has been developed to synthesize the noise produced by an exhaust system from details of the type of engine and the physical configuration of the exhaust. The synthesized noise is then played to a panel of subjects to assess its annoyance. The design of the system can then be changed to produce a less unpleasant sound. Sound measurement from vehicle transmissions can be analysed to match peaks with the position of the engine and the contribution of individual components can be calculated. (TRRL) (Author/TRRL)

  • Availability:
  • Corporate Authors:

    Morgan-Grampian (Publishers) Limited

    Morgan Grampian House, 30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • GOODWIN, W
  • Publication Date: 1990-9-13


  • English

Media Info

  • Pagination: p. 47
  • Serial:
    • Volume: 271
    • Issue Number: 7016
    • Publisher: Morgan-Grampian Limited
    • ISSN: 0013-7758

Subject/Index Terms

Filing Info

  • Accession Number: 00623778
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jul 31 1992 12:00AM