This web page (which is rather elderly itself) has valuable information on the long-lost Auxetophone and its successors and imitators, a family of compressed-air gramophones which were apparently very, very loud
THE AUXETOPHONE: 1898-1918.
Two Englishmen, Horace Short and Sir Charles A Parsons (yes, the steam turbine man) introduced the compressed air amplifiers known as Auxetophones. Horace Short began the development of the idea and was granted a patent in 1898, and again in 1901. The patent rights were sold to Parsons in 1903. Parsons, who was noted for his skill as a craftsman, took on the development of the Auxetophone as a hobby when he was already financially secure from his steam turbine business, and applied it to musical instruments as well as gramophones.