Researchers at the University or Georgia and the Georgia Institute of Technology have successfully used machine learning algorithms to measure stress levels in small groups of broiler chickens, based on their vocalizations. You can ready the summary from Scientific American here:
While this sounds like something out of science fiction, it isn’t that surprising: animal vocalizations must be able to communicate information, or else animals wouldn’t use them. Most of the time, the differences in pitch, timbre, and expression are too nuanced for humans to decode (although the article notes that many farmers, after years of experience with their flock, can detect its general mood). A machine learning algorithm, however, can identify the latent structures common to chicken “speech”, and classify vocalizations into groups with similar structures.
Of course, the structures have to actually be there to be found, but as the algorithms continue to improve–and they are improving very rapidly–this type of application will become more and more common. Who knows: in a few years, Alexa may tell you whether your five-year old really needs a third glass of water.