How acoustics detected artillery in WWI

During WWI, William Lawrence Bragg led the development of an acoustic method to locate enemy artillery, work that was so successful that it was soon used widely throughout the British army. The method, known as sound ranging, was also adopted by the US Army when they joined the war, and earned Bragg a military decoration from the British armed forces. Bragg’s story will be presented at the 177th ASA Meeting, May 13-17, 2019.
Source: EurekaAlert,