The horse relies on a sophisticated system of communication to maintain group cohesion and safety. While much of their interaction happens through subtle body language, vocalizations are important. The sound most recognized by humans is the neigh, often called a whinny, which serves as one of the most complex and far-reaching calls they produce, communicating a specific need or emotional state.
Distinguishing the Neigh from Other Horse Sounds
A horse’s vocabulary includes several distinct sounds, but the neigh stands out. The neigh is a loud, prolonged call that typically begins at a high pitch and gradually lowers, lasting about 1.5 seconds. This acoustic profile allows it to carry a significant distance, sometimes up to half a mile or more.
The neigh contrasts with the nicker, a soft, low-pitched, guttural sound made with the mouth closed and nostrils vibrating. The nicker is an intimate, close-range sound used for friendly greetings, anticipation of food, or between a mare and her foal. Other loud sounds, like the squeal, are sharp and high-pitched, signaling aggression, protest, or defensive behavior. The neigh is fundamentally a contact-seeking or emotional state announcement, not a warning or a close-range greeting.
How Horses Produce the Neigh
The production of the neigh is a physiological process involving a forceful expulsion of air through the respiratory system. Before producing the sound, a horse typically takes a deep breath. The inhaled air is then expelled from the lungs and travels through the larynx, which acts as the voice box. Within the larynx, the horse’s vocal folds, or cords, vibrate to create the sound.
The power of the neigh is directly related to the force with which the air is pushed out of the lungs. The horse often raises its head during this process, increasing the power of the vocalization.
The structure of the neigh is complex, often exhibiting biphonation—the simultaneous production of sound at two distinct frequencies. One frequency component relates to the horse’s emotional arousal, indicating how excited it is. The other conveys emotional valence, signaling whether the emotion is positive or negative. This complex acoustic structure is likely a result of an asynchronous vibration pattern of the vocal cords, which allows the neigh to encode more detailed information about the caller’s internal state.
The Primary Reasons Horses Neigh
The primary function of the neigh is social communication, serving as a long-distance message when visual contact is not possible. The most frequent reason a horse initiates this vocalization is to locate or seek contact with other members of its social group. A horse separated from its herd or a bonded companion will often neigh repeatedly as a contact call, signaling its location and seeking a response.
This is especially evident in the relationship between a mare and her foal, where the neigh is used to maintain contact and provide reassurance when they are out of sight. The sound serves as a question and an announcement, hoping to elicit a return call. The intensity of the call often reflects the degree of separation anxiety or distress the horse is experiencing.
Neighing also serves in individual identification, as subtle variations in the pitch and pattern of the call create a unique vocal signature for each horse. This allows horses to recognize familiar individuals, such as their mothers or close pasture-mates. In a greeting context, horses may neigh upon seeing a companion they have been separated from, or a favored human, expressing excitement or anticipation.
The emotional information contained in the two frequency bands of the neigh allows other horses to quickly assess the caller’s state. A short neigh with a lower high-frequency tone is often associated with positive emotions, such as during a reunion. Conversely, a longer neigh with a higher high-frequency tone signals a negative emotional state, like anxiety or fear.