#optophone

The optophone is a device, used by people who are blind, that scans text and generates time-varying chords of tones to identify letters. It is one of the earliest known applications of sonification. Dr. Edmund Fournier d'Albe of Birmingham University invented the optophone in 1913, which used selenium photosensors to detect black print and convert it into an audible output which could be interpreted by a blind person. The Glasgow company, Barr and Stroud, participated in improving the resolution and usability of the instrument.

(via WIkipedia > Optophone)

The A-2 optophone was tested on three blind research subjects, including ham radio enthusiast Joe Piechowski, who was more of a technical collaborator. According to the reports RCA submitted to the CSD, these readers were able to correlate the “chirping” or “tweeting” sounds of the machine with letters “at random with about eighty percent accuracy” after 60 hours of practice. Close spacing on a printed page made it difficult to differentiate between letters; readers also had difficulty moving the stylus at a steady pace and in a straight line. Piechowski achieved reading speeds of 20 words per minute, which RCA deemed too slow.

Attempts were made to incorporate “human factors” and create a more efficient tonal code, to reduce reading time as well as learning time and confusion between letters. One alternate auditory display was known as the compressed optophone. Rather than generate multiple tones or chords for a single printed letter, which was highly redundant and confusing to the ear, the compressed version identified only certain features of a printed letter: such as the presence of an ascender or descender.