During this time, Tainter worked with the Bells on several inventions, amongst them the photophone and phonograph, which they developed into the Graphophone, a substantial improvement of Edison's earlier device, for which Tainter received several patents along with the Bells. Edison subsequently sued the Volta Graphophone Company (of which Tainter was part owner) for patent infringement, but the case was settled by a compromise between the two.
In 1886, he married Lila R. Munro, and over the next years worked in Washington, perfecting his graphophone and founding a company trying to market the Graphophone as a dictation machine: the first Dictaphone. In 1887 Tainter invented the helically wound paper tube as an improved graphophone cylinder. This design was light and strong, and came to be widely used in applications far removed from its original intent, such as mailing tubes and product containers.
In 1947 Tainter's widow, Laura Fontaine Onderdonk, donated a number of Sumner Tainter's unpublished writings, including the surviving Home Notebooks, to the Smithsonian Institution's National Museum of American History. The Home Notebooks contain daily agendas describing in detail the project work Tainter conducted at the Volta Laboratory during the 1880s. In 1950 Laura Tainter donated other historical items, including Sumner Tainter's manuscripts of "Memoirs of Charles Sumner Tainter", the first 71 pages of which detailed his experiences up to 1887, plus further writings on his work at the Graphophone factory in Bridgeport, Connecticut.
Schoenherr, Steven. Recording Technology History: Charles Sumner Tainter and the Graphophone Archived December 23, 2011, at the Wayback Machine, originally published at the History Department of, University of San Diego, revised July 6, 2005. Retrieved from University of San Diego History Department website December 19, 2009. Document transferred to a personal website upon Professor Schoenherr's retirement. Retrieved again from homepage.mac.com/oldtownman website July 21, 2010. http://homepage.mac.com/oldtownman/recording/graphophone.html
Welch, Walter Leslie & Brodbeck Stenzel Burt, Leah, & Read, Oliver. From Tinfoil To Stereo: The Acoustic Years Of The Recording Industry, 1877–1929, University Press of Florida, 1994, ISBN 0-8130-1317-8, ISBN 978-0-8130-1317-6. https://books.google.com/books?id=1Rz0Z7AT8TwC
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Schoenherr, Steven. Recording Technology History: Charles Sumner Tainter and the Graphophone Archived December 23, 2011, at the Wayback Machine, originally published at the History Department of, University of San Diego, revised July 6, 2005. Retrieved from University of San Diego History Department website December 19, 2009. Document transferred to a personal website upon Professor Schoenherr's retirement. Retrieved again from homepage.mac.com/oldtownman website July 21, 2010. http://homepage.mac.com/oldtownman/recording/graphophone.html
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Bell, Alexander Graham (papers) (1969). The National Union Catalog of manuscript collections 1968: Index 1967-1968. Washington, DC: The Library of Congress. p. 226. http://archive.org/details/trent_0116401849611_1968
Schoenherr, Steven. Recording Technology History: Charles Sumner Tainter and the Graphophone Archived December 23, 2011, at the Wayback Machine, originally published at the History Department of, University of San Diego, revised July 6, 2005. Retrieved from University of San Diego History Department website December 19, 2009. Document transferred to a personal website upon Professor Schoenherr's retirement. Retrieved again from homepage.mac.com/oldtownman website July 21, 2010. http://homepage.mac.com/oldtownman/recording/graphophone.html
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
"Sound Experiments at the Volta Laboratory - Hear My Voice | Albert H. Small Documents Gallery | Smithsonian's National Museum of American History". https://americanhistory.si.edu/documentsgallery/exhibitions/hear-my-voice/6.html
Schoenherr, Steven. Recording Technology History: Charles Sumner Tainter and the Graphophone Archived December 23, 2011, at the Wayback Machine, originally published at the History Department of, University of San Diego, revised July 6, 2005. Retrieved from University of San Diego History Department website December 19, 2009. Document transferred to a personal website upon Professor Schoenherr's retirement. Retrieved again from homepage.mac.com/oldtownman website July 21, 2010. http://homepage.mac.com/oldtownman/recording/graphophone.html
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Smithsonian Institution: Guide to the Charles Sumner Tainter Papers. Collection ID: NMAH.AC.0124. Repository: Archives Center, National Museum of American History. https://sova.si.edu/record/NMAH.AC.0124
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
National Museum of American History. HistoryWired: A few of our favorite things: Alexander Graham Bell and the Graphophone, National Museum of American History, Smithsonian Institution, Washington, D.C. Retrieved from the Smithsonian's HistoryWired.si.edu website, 17 December 2009. http://historywired.si.edu/detail.cfm?ID=187
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm
Harding, Robert S. Charles Sumner Tainter Papers: 1878–1908 & 1919 Archived 2010-03-11 at the Wayback Machine, National Museum of American History, Smithsonian Institution, Washington, D.C., 1984. Retrieved from National Museum of American History Archives Center website, December 19, 2009. http://americanhistory.si.edu/archives/d8124.htm