Here’s a puzzle.
This industrial newsreel profiles Maico hearing aids, among the earliest adopters of transistors.** Like Zenith, Maico made both audiometers and hearing aids. Around 17 minutes, the film shows an interesting gadget that I’ve never heard of before.
The Maico Chromalyzer was used for training deaf speech. The teacher spoke sample words and the Chromalyzer showed a color analysis of the sound. The student would then repeat the word and try to match the same colors. The card to the right is a template or reminder of the proper pattern. I think the screen is showing vowel formants lined up vertically as in the typical spectrogram.
Google doesn’t add any more info. The name Maico Chromalyzer appeared in industry lists in a couple of magazines around 1954, but no ads or articles.
How did it work? It wouldn’t have been a normal CRT, because color TV was just barely starting to develop in 1954. Possibly a vertical stack of colored light bulbs, each responding to a different bandpass filter, with a frosted glass screen in front to blur the image. Reminds me of the Clavecin Oculaire, which was also seen as an aid to the deaf though not intended as such.
I couldn’t resist modeling and animating the Chromalyzer.
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** Bell Labs, following the inspiration of the founder, concentrated heavily on hearing and speech. Most of the important research and ideas in the field came out of Bell. But Bardeen and Shockley weren’t thinking about hearing aids when they developed the transistor. It was just a logical extension of earlier amateur experiments with coupled crystals to simulate a vacuum tube. Still, old Alex would deeply appreciate the earliest commercial use of the Lab’s greatest invention.
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