Dual Tone Multi Frequency

• Wikipedia
  • http://en.wikipedia.org/wiki/Dual-tone_multi-frequency
• Pushbutton Calling with a Two-Group Voice-Frequency Code - The Bell system technical journal [0005-8580] Schenker yr:1960 vol:39 iss:1 pg:235-255
  • This 1960 article sets out the why and how of Dual-Tone Multi-Frequency (DTMF - Touch-Tone) in band audio signaling. It has become one of the most widespread sounds of contemporary planet earth.
  • OpenURL citation for Ex Libris demo site
    • http://demo.exlibrisgroup.com:9003/lr_3?ctx_enc=info%3Aofi%2Fenc%3AUTF-8&ctx_id=10_1&ctx_tim=2007-5-16T13%3A30%3A17CDT&ctx_ver=Z39.88-2004&res_id=http%3A%2F%2Fdemo.exlibrisgroup.com%3A9003%2Flr_3&rft.atitle=Pushbutton+Calling+with+a+Two-Group+Voice-Frequency+Code&rft.aufirst=L&rft.aulast=Schenker&rft.date=1960-01&rft.epage=255&rft.genre=article&rft.issn=0005-8580&rft.issue=1&rft.jtitle=Bell+System+Technical+Journal&rft.spage=235&rft.volume=39&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&svc_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Asch_svc&url_ctx_fmt=info%3Aofi%3Afmt%3Akev%3Amtx%3Actx&url_ver=Z39.88-2004
    • http://tinyurl.com/2qbgvk
  • Microsoft Word document file
    • http://www.porticus.org/bell/doc/dtmf_bell_labs.doc
  • HTML created from Word file with http://www.zamzar.com/
    • http://mshook.python-hosting.com/dtmf/dtmf_bell_labs/
• http://del.icio.us/mshook/dtmf
• http://del.icio.us/popular/dtmf
• http://docs.google.com/Doc?docid=accnfh3pfb3_205hfvzk5rs

t:	dtmf
t:	bell
t:	touchtone
t:	telephone
t:	modulation
t:	1960
Created:	20070701