Horse Verbal Communication
"Name: Equus caballus, the horse.
Runs With The herd.
Recognizes: Individuals within the herd.
Unexpected Talent: Listening. In a new study, University of Sussex, researchers presented a test horse with a herd mate, led the herd mate out of sight and then played a recording of a horse neighing. If it wasn't the herd mate's call, the test animal would tell--it looked fixedly in the direction of the sound, presumably surprised. It's the first demonstration of 'cross-modal' recognition in animals; they identify each other by both sight and sound."
February 2009 Smithsonian Magazine