A study published in 2024 has explained how horses make their loud whinny sound. Horses use this sound to communicate with other horses, especially during social activities. Scientists studied this sound because horses can produce both low and high sounds at the same time. This is uncommon for large animals. The research was done by an international team working at animal research centers in Europe.

The researchers used modern tools to study the horse voice. Small cameras were placed inside the nose, and scans were taken of the voice box. Airflow tests were also done on preserved voice boxes. The study showed that two sound actions happen at the same time. The low sound comes from tissues in the voice box that vibrate. The high sound is made when air passes through a small opening and creates a whistle. Scientists reported that horses are the largest animals known to make this type of sound inside the voice box. This ability may help horses share more information when communicating with others.