We can quickly tell by the tone of a friend's voice if they're feeling excited, tired, or angry. Humans are smart like that. Technology, not so much.

But companies like Facebook are working on dialing up their emotional intelligence game. Facebook has already applied for tons of creepy patents, including one to detect your emotions from your face using the camera on your device. But a patent application does not mean the technology is being developed.

Here's one emotions-reading technology they do appear to be working on, based on claims from an actual Facebook engineer.

Reading the emotions in your voice.

Facebook machine learning engineer Parthath Shah said the social network is working on technology that can detect people's emotions through their voice, The Telegraph reports. If anger or frustrated are detected, for example, the voice recognition software might respond differently. This would come into play for Portal, Facebook's video calling device.

Shah spoke about these plans at the artificial intelligence ReWork Summit. Right now, he said they're having employees and paid volunteers re-enact conversations to begin learning. He also said they don't have an answer yet, and it's especially difficult "measure satisfaction."

Since the project is still in those early learning stages, you don't need to worry about Facebook listening to your voice -- not yet at least.

A Facebook spokesperson told The Telegraph that Facebook's not working on it at all: "Detecting emotion based on the sound of your voice is not on our roadmap and we have no plans to make this a Portal feature or a feature of any other Facebook product."

The artificial intelligence wars are on.

Being able to "read" your voice is the next frontier for artificial intelligence. Amazon filed for a patent last year that could tell if people were sick based on their voice. They could then target you for relevant products and ads, like cough syrup or cold meds. The technology could also determine your gender, age, or ethnic origin based on your voice.

Though Facebook doesn't have a smart speaker, they have Portal. The social network launched the video camera last year, fresh off several privacy scandals that left many users concerned about Facebook's privacy practices. Portal is a device you can use to video chat people through Facebook messenger. This raised concerns that Facebook would try to spy on users through the cameras.

And now users have one more piece of biometric data to try to protect -- all the revealing data in their voices.