In 2015, scientist Elodie Briefer discovered that when horses whinny, they\u2019re actually making two sounds at once \u2013 a low sound and a high sound. Recently, her team explored how horses make their high-pitched sound. Dr. Briefer and her team wanted to try to answer these questions. Using a small camera fed in through the horse\u2019s nose, the researchers were able to watch the voice boxes of different horses as they whinnied. <\/p>\n They found that when the horses made low-pitched sounds, their vocal cords were vibrating, just like when humans talk.<\/p>\n But when the horses made the high-pitched sounds, their vocal cords didn\u2019t move. Instead, the muscles around the voice box tightened, creating a small opening. The researchers believed the horses used this tiny opening to make a whistling sound.<\/p>\n To test their idea, the scientists ran an experiment using helium and air on voice boxes from horses that had died. Compared to regular air, helium will make a whistle sound higher, but it has no effect on vibrating vocal cords. <\/p>\n Sure enough, the whistling sound from the horses\u2019 voice boxes went higher when the scientists blew helium through them. But vibrating the vocal cords with helium instead of air made no difference in sound.<\/p>\n Mice and rats also sometimes make whistling sounds, but horses are the only animals known to make both kinds of sounds at the same time. <\/p>\n Studying Squeaky Sneakers<\/p>\n Adel Djellouli is a Harvard scientist who studies materials. As he watched a Boston Celtics basketball game, he kept noticing the squeaking sound made by the players\u2019 sneakers.<\/p>\n \ud83d\ude15<\/p>\n
(Source: Elodie Briefer [CC BY-SA 4.0<\/a>], Current Biology <\/a>.)<\/p>\n![\"Horse](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/03\/low-res-briefer-e-horse-whinny-1200.jpg\")
The scientists found that when the horses made low-pitched sounds, their vocal cords were vibrating, just like when humans talk. But for the high-pitched sounds, the muscles around the voice box tightened, creating a small opening, which allows them to make a whistling sound.
(Source: Elodie Briefer [CC BY-SA 4.0<\/a>], Current Biology <\/a>.)<\/p>\n
![\"Visualization](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/03\/si-1-shoe-hand-frame-1200.jpg\")
The researchers found that small areas of the shoe sole would slip and then grab again thousands of times a second. Though tiny, these vibrations were faster than the speed of sound. That repeating pattern of tiny slips causes the squeaks.