Girl speaking into a Chromalizer, fromĀ The Mind, a LIFE Science Library Book, by John Rowan Wilson and the Editors of TIME-LIFE Books. (1964, reprinted in 1971).

"The colored panels tell her visually when she is making the right sound."

The True Book of Sounds We Hear, 1960.
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The True Book of Sounds We Hear, 1960.