The Japanese war tuba (Known in Japanese as: 九〇式大空中聴音機, "Large air sound detector ninety formula") is a colloquial name sometimes applied to Imperial Japanese Army acoustic locators due to the visual resemblance to the musical tuba. The name derived from a misidentification, possibly in jest, of a historical photo from the 1930s featuring the Japanese emperor Shōwa inspecting the acoustic locators with anti-aircraft guns in the background.