The Collaborative International Dictionary of English v.0.48:
Egophony \E*goph"o*ny\, n. [Gr. ?, ?, goat + ? voice.] (Med.) The sound of a patient's voice so modified as to resemble the bleating of a goat, heard on applying the ear to the chest in certain diseases within its cavity, as in pleurisy with effusion. [1913 Webster]