Jean Massieu (1772 -1846) was born Deaf & became a teacher of the Deaf. Louis Laurent Marie Clerc (1785 -1869),"The Apostle of the Deaf in America" was taught by Massieu & l'Abbé Sicard (1742-1822). Moving to the U.S.A. with Thomas Gallaudet, Clerc co-founded the school in Connecticut which is now The American School for the Deaf.
A collection of the most remarkable definitions and answers of Massieu and Clerc, Deaf and Dumb, to the various questions put to them, at the public lectures of the Abbé Sicard, in London, to which are joined The manual alphabet of the Deaf and Dumb, the Abbé's Introductory Discourse, and a letter explanatory of his system, by M. Laffon de Ladebat with notes and an English translation by J.H. Sievrac, 1815. (Action on Hearing Loss Library).