Optophone
Hacker News
February 20, 2026
AI-Generated Deep Dive Summary
The Optophone, invented by Dr. Edmund Fournier d'Albe in 1913, revolutionized assistive technology for visually impaired individuals by converting printed text into sound patterns. This groundbreaking device used selenium photosensors to scan text and generate time-varying chords of tones, allowing users to identify letters through auditory feedback. As one of the earliest applications of sonification, the Optophone laid the foundation for modern text-to-speech technologies.
Though initially slow, with early demonstrations achieving only one word per minute, advancements by companies like Barr and Stroud improved its usability and resolution. Later models enabled speeds up to 60 words per minute, though this depended on the individual's ability to interpret the tones. The Optophone's development was documented in scientific papers and articles, including works by d'Albe himself and later studies that explored its potential for reading machines.
The device's tone-generating method, as seen in the FM-SLIT reading machine, demonstrated the feasibility of translating visual information into an accessible auditory format. This innovation not only aided the blind but also highlighted the importance of sonification in communication technologies. While the Optophone was limited in production and adoption during its time, its legacy endures as a precursor to contemporary assistive technologies, underscoring the
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Originally published on Hacker News on 2/20/2026