Michau, [sic] a horn player, visited Philadelphia some years since.  A performer of great executive abilities, whose horn became under his gigantic powers, a violin, a clarionet, a flute, or any thing in short that he chose to make it. – The instrument itself is confined to very few notes. Part of them at harmonical distances, and all in the major mood.  But adagios in the minor keys – diatonic and even chromatic passages as well as harpeggios, flowed as freely in his performances as they could under the fingers of the nimblest pianist. His tone was most thrillingly sweet, and seized the feelings of his auditors like magic.  He was also a respectable composer.
He did not continue longer than a few months in Philadelphia, but before he departed, he gave one concert, and though many had heard him in private with sensations which none but the masterly skill and feeling of such a performer can inspire, he actually lost by this single call upon public liberality.  He contrived however, by teaching military bands and playing at dances, to secure a scanty subsistence during his residence in America.  He returned to France of which he was a native, and has not since been heard of.  Whether he still exists in the herd of great performers, which inhabit that country or is deceased, is not ascertained.
[Euterpeiad, vol. II, no. 2 ( 19 January 1822), p. 170]

MICHAULT ou MICHAUD, violoniste depuis 1770 à l’orchestre de l’Opéra, fit graver, en 1780, son second oeuvre, composé de six duos pour violon.  Un autre virtuose du même nom se distingua, vers 1788, sur le cor.
[Alexandre-Étienne.Choron et François-Joseph-Marie Fayolle, Dictionnaire Historique des Musiciens, Valade, Paris, 1811, Tome 2, p.49] 

On 15 April 1783 a Michault made his debut at Concert Spirituel playing the premier of a violin concerto by Chartrain, followed by a second appearance with another violin concerto (composer not indicated) on 23 December the same year.
[Constant Pierre, Histoire du Concert Spirituel Société Française de Musicologie, 2000, p. 208 and  items 1096 (p. 322) and 1115 (p. 324]
On 15 August 1788 a Michault performed a Duo de cors de chasse with Frédéric Duvernoy, who was a member of l’orchestre de la Comédie italienne. Constant Pierre commented “More than ever the horn had its followers, thanks to Rodolphe and to Punto who had put it in favor.  Dewert (1777), Kohl, (1778-79), Dornaus brothers (1782), Hey (1785), Michault (1788) appeared without giving place to particular reflexion on behalf of the listeners.  As for the amateurs of "innovations", they formerly found satisfaction in an exhibition as not very common as today where however the eccentricities are not precisely rare.
[Pierre, Histoire, pp. 215-16 and item 1238, p. 340. “Plus que jamais le cor eut ses adeptes, grâce à Rodolphe et à Punto qui l’avaient mis en faveur. Dewert (1777), Kohl, (1778-79), Dornaus frères (1782), Hey (1785), Michault (1788) parurent sans donner lieu à réflexion particulière de la part des auditeurs. Quant aux amateurs de “nouveautés”, ils trouvèrent satisfaction dans une exhibition aussi peu commune autrefois qu’aujourd’hui où pourtant les excentricités ne sont pas précisément rares.”]
Birchard Coar lists Jean-Emmanuel Michault as tied for second prize (with Jean Louis Constant Atrapart) in the 1812 concours pour le cor at le Conservatoire National de Musique et Déclamation, Paris. Henri Domnich (ca. 1761-1844) was professeur du cor and there was no first prize awarded that year.
[Birchard Coar, 1952, p.159 quoting Constant Pierre, le Conservatoire National de Musique et Déclamation, 1900, pp. 641-45.]