Microsoft went shopping this weekend. The tech giant has acquired speech tech company Nuance for $19.7 billion. Nuance’s software, called Dragon, is an industry leader for transcription accuracy and uses deep learning to transcribe speech. It also improves accuracy by adapting to a user’s voice. Dragon has been used to license tech like Apple’s famous Siri but it’s unclear how much Siri actually relies on Dragon. This acquisition will be Microsoft’s second-largest after it bought LinkedIn in 2016 for $26 billion. Microsoft says Nuance’s technology can be further integrated in Microsoft teams, or offered independently as part of its Azure cloud business.