The other day I was wondering if it was possible to use compressed air to amplify sound, and after a few hours of fruitless brainstorming a friend found an extant technology that does exactly that: the auxetophone.
Douglas Self, auxetophone, steam audio, Parsons, Edison
"Have you heard the auxetophone? It is to be hoped not. All Mr. Parsons' turbines will be wanted to take long-suffering humanity out of earshot of his diabolical invention"
Here's one of the few videos of it in operation, and it sounds... well.
I can't tell how much of the hiss and tinny quality is from the original phonograph recording versus from the auxetophone itself, but it clearly both 1) works and 2) sounds bad. It works very similarly to a tornado siren, the biggest difference being that the sheet of metal slats reciprocates irregularly (with the waveform to be amplified) rather than rotating continuously. And it's about as loud as a tornado siren, too.
I'm sure you could create a volume control that makes it more bearable, but electric amplification came out only a few years later and is so much better so there's not much reason to iterate on the auxetophone as an audio technology. Still, it's always sick as hell to do something modern without electricity!
