Charles Sumner Tainter (April 25, 1854 – April 20, 1940) was an American scientific instrument maker, engineer and inventor, best known for his collaborations with Alexander Graham Bell, Chichester Bell, Alexander's father-in-law Gardiner Hubbard, and for his significant improvements to Thomas Edison's phonograph, resulting in the Graphophone, one version of which was the first Dictaphone.

[1] Later in his career Tainter was associated with the International Graphopone Company of West Virginia,[2] and also managed his own research and development laboratory, earning him the title: 'Father Of The Talking Machine' (i.e.: father of the phonograph).

[1] 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 1888 he was stricken with severe pneumonia, which would incapacitate him intermittently for the rest of his life,[3] leading him and his wife to move to San Diego, California in 1903.

[1][3][6] The Home Notebooks contain daily agendas describing in detail the project work Tainter conducted at the Volta Laboratory during the 1880s.