So you are serious about developing smart voice interactive applications? The AcuEdge ZLK38AVS Development Kit for Amazon Alexa can help. It features the ZL38063 audio processor and Stereo Acoustic Echo Cancellation for far-field voice interaction.
The kit is available in one to 3 configurations for up to 360-degree pickup. You can attach it directly to a Raspberry Pi 3B. It has a LED ring to report the detected sound location. Costs $299.