I found this today on Googles work on AI Voice Recognition

“A long-standing goal of human-computer interaction has been to enable people to have a natural conversation with computers, as they would with each other. In recent years, we have witnessed a revolution in the ability of computers to understand and to generate natural speech, especially with the application of deep neural networks (e.g., Google voice search, WaveNet). Still, even with today’s state of the art systems, it is often frustrating having to talk to stilted computerized voices that don’t understand natural language. In particular, automated phone systems are still struggling to recognize simple words and commands. They don’t engage in a conversation flow and force the caller to adjust to the system instead of the system adjusting to the caller.”

 

Here are examples of Duplex making phone calls (using different voices):

Duplex scheduling a hair salon appointment:
Duplex calling a restaurant:


Read More
https://ai.googleblog.com/2018/05/duplex-ai-system-for-natural-conversation.html