I had a number of 'loths* capable of overhearing the next ten words or so after you spoke their name aloud, though it was always a question of it being something intrinsic about them or because one PC had a yugoloth created artifact embedded in his ankle, and the next campaign because a PC was related to Larsdana Ap Neut.
*The Oinoloth, Helekanalaith the Keeper of the Tower Arcane, and Larsdana Ap Neut the previous and future Keeper