Guru
Joined: 28/05/2012
Location: GermanyPosts: 1143
| Posted: 11:33am 05 Jan 2023 |
Hi,
I have found a very interesting Android application:
https://warmplace.ru/soft/phonopaper/
It looks like a digital implementation of "Pattern Playback" from 1950 to me (https://120years.net/wordpress/pattern-playback-franklin-s-cooper-usa-1949/).
( https://entokey.com/speech-perception/ )
The Android/Ios program records a sonogram, which can be printed (or displayed on the screen) and read back in with the camera and turned into sounds. The whole thing then sounds similar to turning a record by hand.
The sonogram is obviously another representation of a Fourier transform.
I have long been enthusiastic about the principles of sound recording but I have not heard of this system until now.
Now for my questions:
How can I generate such a sonogram (without this program, maybe with an PicoMite)?
How was the sonogram actually created in 1950??? The reproduction with the tone wheel is plausible, even if the optical beam path is not completely understandable to me...
My goal would be to print a spiral (similar to a vinyl record) and play it back. But the whole thing without a camera, but maybe with a CCD line?
Anyway, I find the whole topic very exciting!
Frank