Let me tell ya folks, it's disgraceful, it's fake news - nothing to do with college brass bands or sousaphones !
"The impressive array of Japanese war-tubas belong to at least two acoustic locators mounted on 4-wheel carriages. It is a little difficult to work exactly what is connected to what, not least because the background appears to have been erased by some unsubtle retouching, but I think that the format is the same as the British model; there are two horns in a horizontal plane, and on one side of the mounting there are two more in a vertical plane. The equipment was called the 'Type 90 Large Detector'. There was a smaller version called the 'Type 90 Small Detector'. See below.
To the right, one of the figures is the Japanese emperor Hirohito. Behind him are the AA guns intended to be used in conjunction with the locators. The only Japanese gun that I have found documented as being used with a sound locator is the Type 88 dual-purpose AA/coast-defence 75mm; there is not enough visible detail to verify that these are the guns shown in the picture, but they look about the right size."
