The influence of high‐intensity sounds on the performance of air warning sirens

Abstract

The use of sirens as air warning devices has been widespread for several hundred years. Due to the very high sound‐pressure levels generated, finite‐amplitude effects can result in large losses leading to poor sound generation efficiency. Although much work has been done on siren design, the importance of finite‐amplitude effects has been neglected in the recent past, even though a review of earlier works shows that researchers such as Reyleigh, in 1903, King, in 1919, and later, Hart, in 1926, noticed the extra acoustic losses associated with high‐intensity sound sources. Comparisons between linear and nonlinear models of wave propagation in a siren horn illustrate the importance of these types of losses, and show how they can be minimized. Acoustic saturation, which limits the sound‐pressure level that can be perceived by a receiver at a given distance from a high‐intensity sound source, and the implications of finite‐amplitude effects on the rating of high‐intensity sound sources in a laboratory environment are also discussed.