Researchers Figure Out How to Interpret Pig Grunts as Pig Emotions

If you've heard one porcine grunt, you haven't heard them all. There's a lot of communication happening through pig sounds, if you know what to listen for. A team of researchers has come up with a translator of sorts for pigs. It's a computer algorithm that interprets all those different pig grunts as emotions.

Understanding animal emotions can help with improving animal welfare and care. Animal behavior researcher Elodie Briefer of the University of Copenhagen is the lead author of a study on the classification of pig calls published in the journal Scientific Reports on Monday. 

To build the equivalent of a grunts-emotions dictionary, the researchers recorded over 7,400 sounds from 411 pigs, tracing their life experiences from birth through death. The team correlated the different calls with the pigs' activities and body language. 

The animals had positive emotions when nursing, reuniting with family, cuddling with litter mates and running freely. Negative emotions came from situations involving social isolation, fights, castration and waiting in a slaughterhouse.

"There are clear differences in pig calls when we look at positive and negative situations. In the positive situations, the calls are far shorter, with minor fluctuations in amplitude. Grunts, more specifically, begin high and gradually go lower in frequency," Briefer said in a statement. "By training an algorithm to recognize these sounds, we can classify 92% of the calls to the correct emotion."

The study is part of the SoundWel project, which aims to help professionals "monitor and improve pig welfare by minimizing stress and encouraging positive emotions." Briefer said the next step could involve developing the algorithm into an app for farmers. Perhaps it could be called Instagrunt...