optophone

File:Optophone in detail.jpg

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,{{cite journal|last=d'Albe|first=E. E. F.|title=On a Type-Reading Optophone|journal=Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences|date=1 July 1914|volume=90|issue=619|pages=373–375|doi=10.1098/rspa.1914.0061|bibcode=1914RSPSA..90..373D|doi-access=free}} 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.{{Citation

|title = The Type-Reading Optophone

|first = E. E. Fournier

|last = d'Albe

|journal = Scientific American

|pages = 109–110

|date = October 1920

|url = http://statisfactions.com/wp-content/uploads/2011/12/opto1920.pdf

|access-date = 2011-12-01

|archive-url = https://web.archive.org/web/20120426010820/http://statisfactions.com/wp-content/uploads/2011/12/opto1920.pdf

|archive-date = 2012-04-26

|url-status = dead

}}

Only a few units were built and reading was initially exceedingly slow; a demonstration at the 1918 Exhibition involved Mary Jameson reading at one word per minute.{{Citation

| title=The Optophone: Its Beginning and Development|

author=Jameson, M.|

journal=Bulletin of Prosthetics Research|

pages=25–28|

year=1966 |

url=http://www.rehab.research.va.gov/jour/66/3/1/25.pdf

}} Later models of the Optophone allowed speeds of up to 60 words per minute, though only some subjects are able to achieve this rate.{{Citation |

title=An audio display for the blind|

author=Fish, R.M.|

journal=IEEE Transactions on Biomedical Engineering|

volume=23|

issue=2|

pages=144–154|

year=1976|

publisher=IEEE

|doi=10.1109/tbme.1976.324576|

pmid=1248840}}

File:Tone generating method of the FM-SLIT.PNG