Robert Sonkin was born into an orthodox Jewish family in The Bronx, New York, in 1911. Sonkin, who held degrees from both City College (now the City College of the City University of New York) and Columbia University, founded the speech clinic at City College. He met Charles L. Todd while they were both working in the Department of Public Speaking at City College in the late 1930s. In addition to the ethnographic research Sonkin did with Todd in California, Sonkin also documented the African American community of Gee's Bend, Alabama, where other FSA work was being carried out. After the onset of World War II, he participated in an Archive of American Folk Song-sponsored project to document the man-in-the-street's opinion of the war effort. Like Todd, Sonkin was drafted into the military during World War II, where he served in the Army Signal Corps.
At the end of the war, Sonkin returned to City College, where he retired in 1976 and later became professor emeritus of speech. Todd and Sonkin once again undertook a collaborative project during this period, which resulted in a book titled Alexander Bryan Johnson: Philosophical Banker, published in 1977. Robert Sonkin died in 1980 at the age of sixty-nine.