Microsoft is acquiring conversational AI startup Semantic Machines in an effort to make bots and intelligent assistants like Cortana sound and respond more like humans. Founded in 2014, Semantic Machines uses machine learning to make bots respond in a more natural way to queries. Semantic Machines is led by UC Berkeley professor Dan Klein and former Apple chief speech scientist Larry Gillick. Both are considered pioneers in conversational AI.

Microsoft’s acquisition will boost the company’s Cortana digital assistant, as well as the company’s Azure Bot Service that’s used by 300,000 developers. Microsoft has already used a human voice for its Cortana assistant. The software maker worked closely with Halo developer 343 Industries on the eyelike visual elements and voice actress Jen Taylor for the voice of Cortana back in 2014. “With the acquisition of Semantic Machines, we will establish a conversational AI center of excellence in Berkeley to push forward the boundaries of what is possible in language interfaces,” explains David Ku, chief technology officer of Microsoft AI & Research.

Google is also working on similar human-sounding AI. The search giant showed off its Google Duplex work earlier this month, which allows the Google Assistant to call businesses and book hair appointments or restaurants on behalf of Google users. Google’s demonstration opened up a number of concerns over casual human speech and deeper concern over ethics. Microsoft has already had its own controversial problem with its own AI thanks to its racist Tay Twitter bot, so you’d imagine it will be very careful with whatever it develops from its acquisition of Semantic Machines.