Case study on the audibility of siren-driven alert systems

Abstract

The civil security sirens are used by the authorities in a wide range of countries to signal an imminent or ongoing threat. Even if their sound level is known, it is nevertheless difficult to evaluate their audibility across a given zone, especially in complex urban environments. An experimental protocol was deployed around a siren installed in a town in France, to assess its audibility perceptually and through modeling. Sound level measurements during source activation were made with the NoiseCapture smartphone application at different distances and on several axes by a group of 25 participants. They were also asked to fill in a questionnaire on perceptual information about the siren such as its audibility, the perceived sound level, or the masking of the siren by passing vehicles. A comparison between acoustic measurement levels using NoiseCapture and simulated sound levels using NoiseModelling was performed. The results of this study validate the use of the Common Noise Assessment Methods in Europe model to evaluate the audibility of a warning system located in an urban environment within a radius of 2.8 km around the siren. Finally, a metric linking audibility to modeled sound level is proposed, enabling the development of siren audibility maps in the study area.

Safe City: A Study of Channels for Public Warnings for Emergency Communication in Finland, Germany, and Greece

“…As indicated by this study, the audibility of alarm sounds can be a problem. However, at the same time, it is important to recognize that optimising the warning siren system placement is not necessarily easy [38]. This study suggests that another issue that requires more consideration is people's awareness of siren use situations and reactions.…”

“…Another problem with siren-driven alert systems is related to their audibility. Optimising the warning siren system placement is a challenging task, particularly in complex urban environments [38].…”

Blind Calibration of Environmental Acoustics Measurements Using Smartphones

“…In the NoiseCapture approach, specific events can be specifically organized in order to collect acoustic data over a defined spatial extent and over a given period. These events, called NoiseCapture Parties, are organized, for example, by researchers to collect data on a specific territory as part of their research into exposure to noise pollution [ 41 , 42 , 43 ], by teachers to train school and university students in environmental noise issues [ 14 ], or by local authorities wishing to raise awareness on the subject of noise environments [ 16 ]. In general, these events are run by professionals who are very familiar with the practice of acoustic measurement in the environment.…”