Acoustic horns photographed on May 31st, 1935

Acoustic horns photographed on May 31st, 1935. Georges Mabboux aimed to improve the "acoustic horns" used for emitting and receiving sound waves. His improvements were focused on "listening to airborne sounds from distant sources". His proposed modifications aimed at optimizing the horns’ walls, whose acoustic reflection would gradually increase while their acoustic transmission would decrease when "moving from the wider opening towards the narrower one". The goal was to mitigate the horns’ distortions, to reduce background noise and to increase their efficiency. On March 20th, 1934, Mabboux applied for a patent, which was issued on May 1st, 1939. In the meantime, radar research had made a breakthrough in detection techniques, rendering these "extended ears" obsolete and almost frivolous. Office national des recherches scientifiques et industrielles et des inventions.