The birds started chirping straight away 🕊️ This incredible real audio comes from the battlefield just as the armistice came into effect. Special units used a technique called ‘sound ranging’ to try to determine where enemy fire was coming drom. To do so, technicians set up strings of microphones and ghen used a piece of photographic film to visually record noise identity. #war #history #warhistory #ww1 #worldwar1 #worldwarone #historytime #historytok