0

Full Content is available to subscribers

Subscribe/Learn More  >

Motor Vehicle Exterior Sound Quality Improvement for Indoors

[+] Author Affiliations
Masao Ishihama, Hiromitsu Sakurai

Kanagawa Institute of Technology

Paper No. IMECE2006-14041, pp. 49-53; 5 pages
doi:10.1115/IMECE2006-14041
From:
  • ASME 2006 International Mechanical Engineering Congress and Exposition
  • Noise Control and Acoustics
  • Chicago, Illinois, USA, November 5 – 10, 2006
  • Conference Sponsors: Noise Control and Acoustics Division
  • ISBN: 0-7918-4776-4 | eISBN: 0-7918-3790-4
  • Copyright © 2006 by ASME

abstract

The objectives of this study are these three items. 1) To find better indices than dB(A) for representing annoyances caused by motor vehicle traffic noise along highways. 2) To find the frequency range of motor vehicle exterior noise that should primarily be controlled to achieve better indoor sound environment along highways. 3) To find suitable vehicle driving conditions for evaluating indoor sound environment. To obtain the desired results psycho-acoustic experiments were conducted. Firstly, sound samples were collected with microphones placed at such locations as on a sidewalk, in front of a small house and at the center of a room inside of the house. The number of test vehicles was fifteen, consisting of six motorcycles and nine passenger cars. The driving conditions were full acceleration and mild acceleration usually found in normal traffic flow. Secondly, semantic differentiation method was used. Ten pairs of adjectives were used to scale the impressions of each sound sample. Finally, physical characters of the sound samples and their subjective evaluations were compared. The results were obtained as follows. 1) Six sound samples got more uncomfortable impression at indoors. These sound samples were collected by vehicles with sport-type mufflers. 2) The samples that indoor sound quality is degraded than outdoor contain high power in low frequency range below 200 Hz. These low frequency components penetrate through the housing walls more easily than higher frequency components. 3) The degradation of comfort impression was found in mild acceleration conditions. The low frequency components of sound samples for mild acceleration are larger than those for full acceleration. Though the throttle is not fully open in mild acceleration, low engine speed generates low frequency components, and eventually increased indoor sound power in the frequency range. The conclusions drawn from these results are, 1) Indoor sound samples should be included for evaluating sound environment along highways. 2) Mild acceleration is a better driving condition for evaluating indoor sound environment along highways. In this condition, very low engine speed causes low frequency component emission that penetrate into housing more than in heavy accelerating conditions. 3) Engine exhaust systems that emit very loud low-frequency components should be focused upon in regulating traffic noise. 4) Extensive collection and analysis of housing sound insulation, absorption and resonance data along highways are necessary for further investigations. 5) Better psycho-acoustic experiment methods should be developed for investigating sound context effects on panelists.

Copyright © 2006 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In