Ludimar Hermann

Ludimar Hermann (October 31, 1838 – June 5, 1914) was a German physiologist and speech scientist who used the Edison phonograph to test theories of vowel production, particularly those of Robert Willis and Charles Wheatstone. He coined the word formant, a term of importance in modern acoustic phonetics. The Hermann grid is named after him; he was the first to report the illusion in scientific literature.