He was a phonologist and sociolinguist, specializing in the field of African languages.
He taught at the State University of New York (SUNY), Binghamton, for 22 years.
For some years in the 1990s, Herbert was professor and head of the Department of African Languages at the University of the Witwatersrand, in Johannesburg, South Africa.
His academic work extended to an important hypothesis on the genesis and transmission of "isihlonipho sabafazi", that is, the complex system of linguistic avoidance traditionally acquired by married Xhosa women (also called the Xhosa women's "language of respect").
In 2005, Herbert became the provost of Youngstown State University as well as a vice president for academic affairs.