EFFECTIVENESS OF AUDIBLE WARNING DEVICES ON EMERGENCY VEHICLES

The purpose of the study was to examine the effectiveness of audible warning devices (AWD's) on emergency vehicles in terms of aural detectability. Community noise intrusion and opportunities for AWD optimization were also investigated. Measurements were made of sirens, automobile insertion loss, and human detection performance in real-life and simulated situations. Warning effectiveness distances were calculated for three representative situations: (1) Rural environment with vehicle windows closed and radio on; (2) urban environment with vehicle windows open and radio off; and (3) suburban environment with vehicle windows open and radio off. It was concluded that reliance on present audible warning devices to warn drivers in traffic is not justified. To be loud enough to warn in all ordinary circumstances, the sound level of audible warning devices would have to be increased greatly -- producing intolerable community noise. Present audible warning devices can be improved; more uniform horizontal forward radiation and higher frequency sounds would increase detectability. The analysis procedure can provide the basis for an objective measure of audible warning device performance.

• Supplemental Notes:
  • Prepared by Bolt, Beranek and Newman, Inc., Cambridge, Mass.
• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096

  Bolt, Beranek and Newman, Incorporated

  50 Moulton Street
  Cambridge, MA  United States  02138

  Transportation Systems Center

  55 Broadway, Kendall Square
  Cambridge, MA  United States  02142
• Authors:
  • Potter, R C
  • FIDELL, S A
  • Myles, M M
  • Keast, D N
• Publication Date: 1977-8

Media Info

• Pagination: 150 p.

Subject/Index Terms

• TRT Terms: Auditory perception; Emergency vehicles; Environmental impacts; Grade crossing protection systems; Human factors; Loudness; Measures of effectiveness; Motor vehicles; Noise; Optimization; Rural areas; Safety; Simulation; Sirens; Sound level; Suburbs; Urban areas; Warning systems
• Uncontrolled Terms: Effectiveness
• Old TRIS Terms: Audible warnings; Grade crossing protection
• Subject Areas: Environment; Highways; Railroads; Safety and Human Factors;

Filing Info

• Accession Number: 00169215
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: DOT-TSC-OST-77-38 Final Rpt., HS-021 948
• Contract Numbers: DOT-TSC-868
• Files: NTIS, TRIS
• Created Date: Jan 30 1989 12:00AM