In Greek myth, the sirens were women with the bodies of birds whose song was so alluring that it enticed men to their death. In the early 19th century, French engineer and physicist Charles Cagniard de la Tour built a device that sent blasts of air...
wash-out effect n.— «In the early 1970s, manufacturers introduced sirens with different patterns and frequencies, to address a growing problem: Officers in different police cars using the same frequency often could not hear each other...
