Our party was in town warning them about gnoll attacks. We were talking to a farmer, and were, for reasons I don't remember, talking about his chickens. He had said that they were too loud and he would appreciate them being quieter.

Our Warforged Cleric (this is a D&D 4th edition game) decided to go to the chickens and cast a Silence ritual, which prevents noise from leaving a 3x3 area. After it finished the ritual, it and the chickens were attacked by hyenas. The cleric tried to warn us, but we couldn't hear it because of the silence zone.