Fundamental Frequency of Sound as Unique Animal Communication

 

Human auditory perception is so complex that we have the ability to distinguish people based on the slightest differences in their voice. The differences go beyond just pitch or volume, and many people use the word "color" to describe the specific tonal specialty of an individual, whether they are singing or simply talking. This "color" is what makes us instantly turn when hearing someone we know instead of lumping all background voices together. This "color" has a technical term; fundamental frequency, or F0, and this determines the uniqueness of human voice, and also, animals 'voices' too.

The paper "Auditory biological marker of concussion in children" by Nina Kraus et. al. relates fundamental frequency and other aspects of auditory processing to how brain damages experienced after a concussion. By comparing graphs of auditory perception from an individual pre and post traumatic brain injury, it can be determined whether damage has been done from said injury and whether it is to the extent of a concussion. Since concussions have no acute diagnostic test, being able to observe damage in this way could be a very beneficial diagnostic tool. Fundamental frequency, then, is a highly complex and special feature of auditory production and processing.

Furthermore, Kraus et. al. states that "tracking the F0 facilitates pitch perception, identifying sounds and talkers, and understanding stress and prosody," (Kraus, 2016) so not only is our processing of F0 useful for identifying the owner of a sound, but also what to interpret from the sound, on a very subtle level. This could mean that outside of intentional tone used by an individual when speaking, the very F0 of their voice could dictate some level of tonal perception as well. Maybe some fundamental frequencies innately have an off-putting expression, and some are more calming and inviting. This could be an explanation for certain "vibes" people may put off when they speak, an intangible perception others receive audibly that affects how they perceive the person as a result.

Humans are not the only creatures who have a fundamental frequency of sound, but animals do as well. They communicate in their own ways and can probably distinguish members of their species similarly to how humans do. However, there is one animal who has an extra layer of uniqueness to their fundamental frequency and sound they produce, and that is the horse. Horses have long been known to have a unique sound when they whinny, but now it is understood how; in one sound, horses produce two fundamental frequencies. There is a low-pitched sound from vibrating the larynx, like when humans sing, and simultaneously there is a high-pitched whistling from the vocal cords, unusual to most large animals. In a statement to Scientific American by co-author of the paper that discusses these findings, Élodie Briefer says “In the past, we found that these two frequencies are important for horses, as they convey different messages about the horses’ own emotions,” (Briefer, 2026). I think it is interesting that horses are one animal that has evolved to have two separate mechanics of sound production. There are birds for example that can produce two separate whistle sounds simultaneously, but they come from the same system, unlike the whistling and vibration patterns of a horse's whinny.

Both the paper by Kraus et. al. and the study about horses illustrate a unique auditory concept, fundamental frequency, and show how it has great value among humans as well as other animals. of sound. The findings about horses and how their F0 is a factor in their emotional communication could provide insight into how F0 conveys emotion and tone, and this could translate into human communication as well. Fundamental frequency is an evolutionarily conserved mechanism for communication in specifying certain things, like owner and pitch, but there is something extra special about the way horses have evolved with it, allowing them to produce multiple F0s through different mechanisms. I am interested to see where these findings take scientists in the fields of neuroscience, auditory mechanisms, and human and animals processes.

 

References:

Kraus, Nina et. al. 2016. Auditory biological marker of concussion in children. Scientific Report retrieved from Nature.com

Mogensen, Jackie Flynn. “Horses Whinny by Making Sounds in a Unique Way That Is Not Seen in Other Animals.” Scientific American, Scientific American, 25 Feb. 2026, www.scientificamerican.com/article/how-horses-whinny-has-long-been-a-mystery-now-scientists-think-they-know-the/.