This article investigates the claims made in the dedicatory epistle to Girolamo Manfredi’s De homine to have effected an Italian translation of various earlier works. First published in 1474, the De homine is strongly dependent on the pseudo-Aristotelian Problems, for which several translations into Latin were available by Manfredi’s time as well as the highly influential commentary by Pietro d’Abano. Focusing on one particular section of the De homine, on voice, this article offers an analysis of the various sources used (...) and of the extent to which Manfredi is indeed offering a translation or something different. This study concludes that Manfredi closely followed the translation by Bartolomeo da Messina and the commentary by Pietro d’Abano; it finds no clear evidence of his use of the translations by George of Trebizond or Theodore Gaza. Other sources used include especially Rhazes’ Ad Almansorem. (shrink)