Can Dogs Hear Shapes? New Italian Study Reveals a Surprising Connection
When people hear the invented word “Bouba,” they usually associate it with a rounded shape. The sharper-sounding word “Kiki,” meanwhile, seems to belong to something pointed or angular. This curious connection between sounds and shapes has fascinated scientists for decades. Now, researchers in Italy have discovered that dogs appear to make similar associations, raising intriguing questions about how animals perceive the world around them.
When Sounds Seem to Have Shapes
Imagine being shown two unfamiliar objects. One has smooth, rounded edges, while the other resembles a jagged star. Someone then asks which object should be called “Bouba” and which should be called “Kiki.”Most people associate Bouba with the rounded object and Kiki with the pointed one, even though neither word has any actual meaning.
Scientists call this the Bouba–Kiki effect. It is an example of sound symbolism, the tendency to associate particular sounds with certain characteristics.The phenomenon has traditionally attracted attention from researchers studying human language. However, a new investigation suggests that the underlying ability may extend beyond our species.Researchers at the University of Parma tested whether domestic dogs would make the same connections without being taught what the invented words meant.
Their findings were published on 14 October in Proceedings of the Royal Society B: Biological Sciences.
Seventy Dogs and Two Invented Words
The research team, led by Eleonora Biffi and Giulia Pedretti, examined the responses of 70 adult pet dogs in two experiments.In the first experiment, 51 dogs entered a testing room with their owners. Two screens displayed different shapes: one rounded and the other angular.Recordings repeatedly played either Bouba or Kiki while cameras monitored where the dogs directed their attention.Each dog participated in four short trials. During the initial observation period, owners kept their dogs in position while the recordings played. Afterwards, the animals were allowed to explore the room.
The researchers used computer-assisted video analysis to measure the direction and duration of the dogs’ attention.The results revealed a significant pattern. Dogs spent more time looking at the rounded shape when hearing Bouba and at the angular shape when hearing Kiki.During free exploration, the dogs also showed greater interest in the pointed shape when Kiki was played.
Could the Owners Have Influenced Their Dogs?
One difficulty in animal-behaviour research is determining whether an animal responds independently or follows subtle signals from a human.This problem is sometimes called the Clever Hans effect, named after a horse that appeared capable of performing mathematical calculations but was actually responding to unconscious human cues.
To address this possibility, the Italian researchers conducted a second experiment involving 19 additional dogs.This time, the owners wore headphones playing music, preventing them from hearing whether Bouba or Kiki was being played.The dogs nevertheless continued to show the same general pattern of visual attention.They looked longer at rounded shapes during Bouba recordings and at pointed shapes during Kiki recordings.However, unlike the first group, these dogs did not show a clear preference for either shape during free exploration.
The researchers also observed that dogs in the first experiment sometimes looked more quickly towards the pointed shape regardless of the sound being played.These differences are important because they suggest that canine perception may not follow exactly the same patterns observed in humans.
What Does This Tell Us About Dog Intelligence?
The findings do not mean that dogs understand the invented words or possess human-like language abilities.Instead, they suggest that dogs may naturally connect information received through different senses.Scientists describe this process as cross-modal correspondence. It occurs when characteristics detected through one sense are associated with information received through another.For example, an animal might associate a high-pitched sound with something small or a deeper sound with something large.Previous research has suggested that dogs can make associations of this kind.
The Bouba–Kiki experiment adds another example, involving the relationship between speech-like sounds and visual shapes.Importantly, the study does not establish whether these associations are inherited, acquired through experience or influenced by domestication.Those questions remain unanswered.
Dogs Are Not the Only Animals Making These Connections
The Italian findings also contribute to a broader scientific investigation into the origins of sound symbolism.Earlier in 2026, researchers reported that very young domestic chicks could associate rounded and angular shapes with Bouba and Kiki.The discovery was particularly interesting because some chicks demonstrated the effect before they had much opportunity to learn such associations.
Together, the studies suggest that connecting sounds and shapes may reflect a general feature of animal perception rather than an ability dependent entirely on human language.Nevertheless, researchers must be cautious when comparing different species. Similar behaviour does not necessarily mean that the underlying mental processes are identical.Further experiments involving puppies, other domestic animals and wild relatives of dogs could help clarify how widespread the phenomenon is.
Dogs have spent thousands of years living alongside humans, developing remarkable abilities to respond to our voices, gestures and behaviour.The new study adds another piece to that relationship, suggesting that dogs may perceive certain qualities of spoken sounds in ways that resemble our own.For dog owners, however, the discovery does not yet provide a new training method or establish that particular commands are easier to learn.
The researchers emphasise that further investigation is needed to understand whether sound symbolism influences how dogs learn words or interpret human communication.For now, the discovery offers something equally valuable: another reminder that the canine mind may process ordinary experiences in ways we are only beginning to understand.
And perhaps the next time someone says Bouba or Kiki, the family dog really does have an opinion about which shape belongs to which sound.
Primary Scientific Sources
1. Original peer-reviewed research
Biffi, E., Pedretti, G., Normando, S., Lazebnik, T., Loconsole, M., & Valsecchi, P. (2026).
Hearing shapes: the Bouba–Kiki effect in adult domestic dogs.
Proceedings of the Royal Society B: Biological Sciences, 293(2080), 20261209.
Read the original scientific paper
2. University of Parma — Official Research Announcement
Published 14 October 2026, updated 15 October 2026.
Effetto Bouba-Kiki: anche per i cani i suoni hanno una forma
This is particularly valuable because it explains the experimental design, the Clever Hans precautions, and the limitations identified by the researchers.
3. Related research involving chicks
Earlier research published in Science examined similar sound-shape associations in newly hatched chicks.
