A framework for the design of ambulance sirens

Abstract

Ambulance sirens are essential for assisting the safe and rapid arrival of an ambulance at the scene of an emergency. In this study, the parameters upon which sirens may be designed were examined and a framework for emergency vehicle siren design was proposed. Validity for the framework was supported through acoustic measurements and the evaluation of ambulance transit times over 240 emergency runs using two different siren systems. Modifying existing siren sounds to add high frequency content would improve vehicle penetration, detectability and sound localization cues, and mounting the siren behind the radiator grill, rather than on the light bar or under the wheel arch, would provide less unwanted noise while maintaining or improving the effective distance in front of the vehicle. Ultimately, these considerations will benefit any new attempt to design auditory warnings for the emergency services.

Keywords:

• Siren
• Ambulance
• Warning
• Alarm
• Safety
• Design

Acknowledgements

These studies were funded by Sound Alert Limited and by the Economic and Social Research Council. The author wishes to thank the West Yorkshire Metropolitan Ambulance Service for their assistance in this project and also to acknowledge Professor Deborah Withington (Sound Alert Ltd and Department of Physiology, University of Leeds) for her assistance with this research and her comments on an earlier draft.