View source for Voder

{{Short description|Electronic voice synthesizer}}
[[file:Homer Dudley (October 1940). "The Carrier Nature of Speech". Bell System Technical Journal, XIX(4);495-515. -- Fig.8 Schematic circuit of the voder.jpg|thumb|400px|Schematic circuit of the VODER<ref name=bell1940a>
{{harvnb|Bell System Technical Journal|1940|loc=[https://archive.org/stream/bellsystemtechni19amerrich/bellsystemtechni19amerrich#page/509/mode/1up Fig.8 Schematic circuit of the voder]|p=509}}</ref>]]
The [[Bell Labs|Bell Telephone Laboratory's]] '''Voder''' (abbreviation of '''Voice Operating Demonstrator''') was the first attempt to electronically [[Speech synthesis|synthesize human speech]] by breaking it down into its acoustic components. It was invented by [[Homer Dudley]] in 1937–1938 and developed on his earlier work on the [[vocoder]].  The quality of the speech was limited; however, it demonstrated the synthesis of the human voice, which became one component of the vocoder used in voice communications for security and to save bandwidth.<ref name=Gold11>Ben Gold, Nelson Morgan, Dan Ellis, ''Speech and Audio Signal Processing: Processing and Perception of Speech and Music''.  John Wiley & Sons, 2011; {{ISBN|1118142918}}, pages 9‒13</ref>
The Voder synthesized human speech by imitating the effects of the human [[vocal tract]]. The operator could select one of two basic sounds by using a wrist bar. A buzz tone generated by a [[relaxation oscillator]] produced the voiced vowels and nasal sounds, with the pitch controlled by a foot pedal. A hissing noise produced by a white noise tube created the sibilants (voiceless [[Fricative consonant|fricative sounds]]).  These initial sounds were passed through a bank of 10 [[band-pass filter]]s that were selected by keys; their outputs were combined, amplified and fed to a loudspeaker.  The filters were controlled by a set of keys and a foot pedal to convert the hisses and tones into vowels, consonants, and inflections.  Additional special keys were provided to make the [[plosive]] sounds such as "p" or "d", and the [[affricate consonant|affricative sounds]] of the "j" in "jaw" and the "ch" in "cheese". This was a complex machine to operate. After months of practice, a trained operator could produce recognizable speech.<ref name=Gold11/>
[[file:VODER demonstrated on 1939 New York World Fair - The VODER fascinates the crowds - Bell Telephone Quarterly (January 1940).jpg|thumb|Voder demonstration by Bell Labs at the [[1939 New York World's Fair]]<ref name=bell1940>{{harvnb|Bell Telephone Quarterly|1940|loc="At the New York World's Fair"|p=[https://archive.org/stream/belltelephonemag19amerrich/belltelephonemag19amerrich#page/64/mode/1up 65]}}, {{smaller|'''THE VODER FASCINATES THE CROWDS''' - "''The manipulative skill of the operator's fingers makes the Voder's voice almost too good to be true''"}}</ref>]]
Performances on the Voder were featured at the [[1939 New York World's Fair]] and in [[Golden Gate International Exposition|San Francisco]].  Twenty operators were trained by Helen Harper, particularly noted for her skill with the machine. The machine said the words "Good afternoon, radio audience."<ref>{{cite news |last=Guernsey |first=Lisa |date=August 9, 2001 |title=The Desktop That Does Elvis |url=https://www.nytimes.com/2001/08/09/technology/the-desktop-that-does-elvis.html |work=The New York Times |access-date=January 21, 2018 |quote=At the 1939 World's Fair in New York City, AT&T Bell Laboratories, a forerunner of AT&T Labs, unveiled a speech machine called the Voder. Six women were trained to operate the contraption, which was played like a pipe organ. When the machine said, "Good afternoon, radio audience," it sounded like an alien speaking under water.}}</ref>
The Voder was developed from research into compression schemes for transmission of voice on copper wires and for voice encryption. In 1948, [[Werner Meyer-Eppler]]<ref name="meyer-eppler">{{citation|first=Sonja |last=Diesterhöft |year=2003 |title=Meyer-Eppler und der Vocoder |url=http://www.kgw.tu-berlin.de/statisch/Studio/Meyer-Eppler/Meyer-Eppler.html |language=de |work=Seminars Klanganalyse und -synthese |publisher=Fachgebiet Kommunikationswissenschaft, Institut für Sprache und Kommunikation, Technische Universität Berlin|archiveurl=https://web.archive.org/web/20080305021509/http://www.kgw.tu-berlin.de/statisch/Studio/Meyer-Eppler/Meyer-Eppler.html |archivedate=2008-03-05}}</ref> recognized the capability of the Voder machine to generate electronic music, as described in Dudley's patent.
Whereas the vocoder analyzes speech, transforms it into electronically transmitted information, and recreates it, the voder generates synthesized speech by means of a console with fifteen touch-sensitive keys and a pedal. It basically consists of the "second half" of the vocoder, but with manual filter controls, and required a highly trained operator.<ref name="wendycarlosQA">{{cite web |title=Wendy Carlos Vocoder Q&A |url=http://www.wendycarlos.com/vocoders.html |publisher=Wendy Carlos}}</ref><ref name="120years-HomerDudley">{{cite web |title=Homer Dudley's Speech Synthesisers, "The Vocoder" (1940) & "Voder"(1939) |work=Electronic Musical Instrument 1870–1990 |url=http://120years.net/machines/vocoder/ |publisher=120 Years of Electronic Music (120years.net)}}</ref>
==See also==
*[[Formant]]
==References==
{{reflist}}
;Bibliography
* {{cite journal |ref={{sfnref|Bell System Technical Journal|1940}} |first=Homer |last=Dudley |publication-date=October 1940 |title=The Carrier Nature of Speech |journal=Bell System Technical Journal |volume=XIX |issue=4 |pages=495–515 |url=https://archive.org/stream/bellsystemtechni19amerrich/bellsystemtechni19amerrich#page/495/mode/1up |quote=Speech synthesizing is here discussed in the terminology of carrier circuits. ... |via=Internet Archive}}
* {{cite journal |ref={{sfnref|Bell Telephone Quarterly|1940}} |last=Williams |first=Thomas W. |title=At the New York World's Fair |department=Our Exhibits at two Fairs |journal=Bell Telephone Quarterly |volume=XIX |issue =1 |publication-date=January 1940 |publisher=American Telephone & Telegraph Co. |location=New York |pages=59–71 |url=https://archive.org/stream/belltelephonemag19amerrich/belltelephonemag19amerrich#page/59/mode/1up |quote=More than Thirteen Million Visitors Enjoyed the Bell System's Hospitality, and Learned about It and Its Services, at the New York Fair and the San Francisco Exposition |via=Internet Archive}}
* {{Ref patent|country=US |number=2121142 |status=application |title=[https://patents.google.com/patent/US2121142 System for the artificial production of vocal or other sounds] |pubdate=21 June 1938 |fdate=7 April 1937 |inventor=Homer Dudley |assign1=Bell Telephone Laboratories}}
==External links==
{{Commons category|VODER}}
*[https://web.archive.org/web/20130728222319/http://www.davidszondy.com/future/robot/voder.htm "The Voder"] – has photos and block diagrams
*{{cite web
| title     = The Voder - Homer Dudley (Bell Labs) 1939
| url       = https://www.youtube.com/watch?v=5hyI_dM5cGo#t=3m00s
| format    = audio + slide
| work      = YouTube
}}{{snd}}Voder singing the Scottish folk song "[[Auld Lang Syne]]" at [https://www.youtube.com/watch?v=5hyI_dM5cGo#t=3m00s 3'00"] (20 sec).
[[Category:Speech synthesis]]