A horse's whinny is unlike any other sound in nature Horses use their larynx to make two sounds simultaneously, so they are effectively singing and whistling at the same time “Horses are the only mammal known to use the larynx to produce two frequencies simultaneously where one is a whistle and, in fact, they’re the only large mammal, besides humans, to produce whistles as part of the standard vocal repertoire,” says Fitch. #horses #sound #whinny https://www.newscientist.com/article/2516446-a-horses-whinny-is-unlike-any-other-sound-in-nature/