Facebook contractors were listening to and transcribing select voice conversations that were held using its Facebook Messenger chat platform, Bloomberg reported on Tuesday. The company reportedly had the contractors transcribe chats in an effort to improve artificial intelligence.

Facebook shares dipped slightly after Bloomberg published its story, but shares were still up more than 1% for the day.

"Much like Apple and Google, we paused human review of audio more than a week ago," a Facebook spokesperson told CNBC.

Other companies have done or are doing the same thing to improve voice recognition in products such as Alexa, Google Assistant and Siri.