This book traces the history of the mythologies of Echo and of the echo, from their starting point in two ancient tales (Ovid, Longus) up to novels by E.M. Forster, Thomas Mann and Christoph Ransmayr, stressing their importance for baroque aesthetics (Sor Juana Iñes de la Cruz, Calderón) and for romanticism (Wordsworth, Keats, Brentano, Hofffmann). It shows how the dialogue with the echo, from Aristophanes’ comedies to Renaissance pastorals and later to modern theater, creates a space for authorial voice. As a feminine figure of desire, Echo becomes the « tenth Muse » for Humanists, and opens up the possibility of representing poetic or musical creation as a creative victory over constraint. In the most recent fictions, the echo also functions to figure anxiety and loss. Above all, confronted to Narcissus in Ovid’s Metamorphoses or to the god Pan in Longus’ Pastorals, Echo offers the lyrical poet a model of discovery of the other in the self and of care for the « song of the world », thus raising the question of the self’s identity. Ultimately, the book thus concludes with a fragmentary portrait of the poet as Echo: from Petrarch to Victor Hugo, Ronsard to Guillaume Apollinaire, Gaspara Stampa to Marceline Desbordes-Valmore, the lyrical subject, beyond gendered differences, tends to define (him)herself as a « sound echo ».