NPR (National Public Radio in the U.S.) is running a series on "Vintage Sounds" -- the disappearance of the sounds of old technology. They're looking for contributions from the public, if anyone happens to know someone with access to a noisy hunk of old machinery. Gee, I might be able to find one around here somewhere...
The first piece ran on Monday and was about film cameras: you can hear the audio and read a transcript on their web site.
To contribute, fill out their contact form with "Vintage Sound" in the subject line.