DEFENDERS: How to stop Facebook from listening to your phone conversations

Facebook has confirmed that it has been listening to your audio Messenger chats. 

The social media giant says it has since stopped a program in which third-party contractors would listen to and transcribe your conversations. 

University of Missouri cyber expert Prasad Calyam said the practice is common in the tech industry. Companies claim it helps improve their service. Calyam, along with other industry experts, says the concern is that users aren't aware that humans, not just computers, are reviewing audio. 

"Usually if you are talking to Alexa or these other devices, the intent is very clear. You're asking for the weather, a restaurant," Calyam said. "The worrisome thing here is that we don't know what action they will take. Why do they want to look at these conversations?" 

Facebook says contractors were checking whether the company's artificial intelligence correctly interpreted the messages. While the practice may be legal, Calyam tells ABC 17 News it's deceiving. 

"As users we don't know what else is happening inside. These companies need to better educate users on what is going on, explain the benefits of their intent, research or give users an option to opt out," Calyam said. 

Here is how you can prevent any Facebook app from accessing your microphone to possibly listen in on any conversation. 

For iPhone users: Go to settings-Facebook, then slide the microphone button to the left, going from green to white, disabling it. 

For Android users: Go to settings-Facebook app-permissions-turn off mic. 

Facebook is now the fourth company to confirm that human contractors are listening to people's private conversations. Apple, Google and Amazon have all been caught in the same practice.