The roots of acoustic location extend back to the late 19th century, even before the invention of aircraft. The earliest rendition of such a device appeared in the pages of Scientific American magazine from 1880. “Professor Mayer’s topophone”, invented and patented by A. M. Mayer in 1879, was intended to assist the wearer in pinpointing the source of any sound. How’s that for Yankee ingenuity!
From the “building a better mousetrap” category comes the Shout-O-Phone, a souped-up version of Professor Mayer’s enhanced ears that boosts the outgoing sound as well. Amazing… not so much the device, but that it took 60 years for it to be produced.
Somebody obviously thought there was potential in Professor Mayer’s brainchild (or brain fart, you decide) because personal, wearable sound-enhancing devices made a number of appearances culminating in the 1960 Brussels Inventor’s Fair where French inventor Jean Auscher demonstrated a device that was supposed to help boaters navigate in case of radar failure – which happens like ALL the time.
It was the invention of the airplane and, soon thereafter, the threat of massive bomber attacks in wartime that concentrated military minds. Some way of detecting warplanes at a distance had to be found, and the most obvious method was enhancedacoustic detection. The above devices were built and used by a number of armed forces with a mixed record of success. The above four-horned acoustic locater was built in 1920s Czechoslovakia and tested in The Netherlands… evidently the nearest noisy place.
Let’s not forget the Americans, carrying on the legacy of Professor Mayer in times of peace and war. The image at above, top, shows a two-hornaircraft detector in use at Bolling Field in Washington DC, in 1921. The lower image depicts a slightly less cumbersome acoustic locator manned by US Army troops in 1943, after radar had been introduced. It should be said that the first Japanese air raids on the American-held island of Corregidor in late December of 1941 were detected byacoustic locators.
The 1930s saw rising tensions in Europe and rapid technological progress in aeronautics. Radar was on the horizon but until the newfangled machines were ready, something had to fill the gap.
As Hitler speedily rebuilt Germany’s war machine in the late 1930s, antiaircraft measures were a high priority. German radar research was far behind developments in Great Britain but that wasn’t the case withacoustic detection, as shown above. Behold, das Ringtrichterrichtungshoerer (or “ring-horn acoustic direction detector”)… RRH for short, used during the Second World war to help aim searchlights at night-flying bombers.
Let’s not forget Japan, though Japan would probably like to forget these bizarre yet magnificent “war tubas”. These were a variation of theacoustic horn listening devices, not an attempt to blow attacking aircraft out of the sky using low-pressure sound waves. That’s Emperor Hirohito reviewing the Imperial War Tuba Brigade in the top photo by the way, so you know they were serious.
The British were well along with large-scale radar installations as the blitzkrieg burst across continental Europe but taking nothing for granted, Churchill’s minions set up a significant number of concrete sound mirrors facing across the English Channel. many of these parabolic shells survive as abandonments today, a testament to a far-off time when wars were low-tech though no less deadly.