Positive Tone Matters when Speaking to Animals: Study

As it turns out, many animals have a sophisticated level of emotional development and can distinguish between positive and negative tones of communication–not only from within their own species, but from humans as well.  Humans who share their homes with domesticated animals like dogs and cats already know this about those animals, but animals who do not live inside human homes can distinguish between between positive and negative human tones as well.  New scientific research in behavioral biology has recently demonstrated that horses, pigs and wild horses can distinguish between negative and positive sounds from their fellow species and near relatives, as well as from human speech.


Part of the aim of the study, was to investigate the possibility of “emotional contagion” in animals – a kind of mirroring of emotion. Situations where one expressed emotion is assumed by another. In behavioral biology, this type of reaction is seen as the first step in the empathy category.  The study was unable to detect clear observations of “emotional contagion”, but an interesting result was in the order by which the sounds where delivered. Sequences in which the negative sound was played first triggered stronger reactions in all but the wild boars. This included human speech. This suggests that the way we talk around animals and the way we talk to animals may have an impact on their well-being.


“It means that our voices have a direct impact on the emotional state of animals, which is very interesting from an animal welfare perspective.” -Dr. Elodie Briefer, researcher, University of Copenhagen’s Department of Biology 

Study overview

“The researchers played recordings of animal sounds and human voices from hidden speakers. To avoid having the domesticated animals react to specific words, positive and negative human speech was performed by a professional voice actor in a kind of gibberish without any meaningful phrases.  The animals’ behavioral reactions were recorded in a number of categories used in previous studies – everything from their ear position to their movement or lack thereof.

On this basis, the researchers concluded that: How we speak matters to animals.


“Our results show that these animals are affected by the emotions we charge our voices with when we speak to or are around them. They react more strongly – generally faster – when they are met with a negatively charged voice, compared to having a positively charged voice played to them first. In certain situations, they even seem to mirror the emotion to which they are exposed.”

The takeaway

The results of this study be used as a concrete means of improving animals’ daily lives.


“When the animals reacted strongly to hearing negatively charged speech first, the same is also true in the reverse. That is, if animals are initially spoken to in a more positive, friendly voice, when met by people, they…may become calmer and more relaxed.”


Journal Reference: Anne-Laure Maigrot, Edna Hillmann, & Elodie Floriane Mandel-Briefer, Cross-species discrimination of vocal expression of emotional valence by Equidae and Suidae, BMC Biology, May 24, 2022. DOI: 10.1186/s12915-022-01311-5